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F Unit guideSimple chemical reactions

© Harcourt Education Ltd 2003 Catalyst 1 This worksheet may have been altered from the original on the CD-ROM. Sheet 1 of 1

Where this unit fits in Prior learningThis unit builds on:unit 6D Reversible and irreversible changes and unit 5D Gases. It builds on unit 7E Acids and alkalis.

The main concept in this unit is: that new substances are made by chemical reactions.

This unit leads onto:other Sc3 units that include work on chemical changes, but particularly unit 9E Reactions of metalsand metal compounds.

Expectations from the QCA Scheme of WorkAt the end of this unit …

… most pupils will … … some pupils will not have made somuch progress and will …

… some pupils will have progressedfurther and will …

in terms of scientific enquiry NC Programme of Study Sc1 1b; 2c, d, e, f, g, h, i, j, k, l, m, n

• obtain and present qualitative results,identifying patterns in these

• work safely with acids and when burningmaterials

• suggest how to test an idea about burning,obtaining results that can be represented asa line graph.

• obtain and present qualitative results,describe some hazards of acids and ofburning

• work safely with acids and when burningmaterials

• test an idea about burning and presentresults.

• also evaluate how well ideas about burningmatch the data collected.

in terms of materials and their properties NC Programme of Study Sc3 1f, 2i, 3a, e, f

• identify that some new materials are formedduring a chemical reaction

• generalise that hydrogen is formed whenacids react with metals, carbon dioxide when acids react withcarbonates, and oxides when materials burn

• describe tests for carbon dioxide andhydrogen

• describe burning as a reaction with oxygen.

• identify some products of chemical reactions• state that oxygen or air is needed for

burning.

• also predict that carbon dioxide and waterwill be made when a hydrocarbon burns

• use word equations to represent reactions inwhich materials burn.

Suggested lesson allocation (see individual lesson planning guides)Direct route

F1Changing materials

F2Acids and metals

F3Acids and carbonates

F4Firefighting

F5Burning changes

F6Getting hotter: Think aboutrelationshipsbetween variables

Extra lessons (not included in pupil book)

F2 Acids and metalsExtra lesson forActivity F2b

F4 Investigate: How much air does aburning candle need?

Review and assessprogress (distributedappropriately)

MisconceptionsMany pupils think that all substances that look the same are the same, e.g. all colourless liquids are water, all colourless gases are air, all whitepowders are the same. It is important to emphasise that they can behave very differently.

Additional information Some teachers may decide to delay the introduction of word equations for some groups. However, the course is written assuming that all pupils will beintroduced to word equations in this unit. The last two lessons in this unit refer to energy as a scientific concept. Teachers will need to take great careto introduce energy carefully if unit I has not been studied.

Health and safety (see activity notes to inform risk assessment)Many chemicals are used in this unit. Hazcards should be used to make the appropriate risk assessment. In general, safety glasses should be worn, allspills wiped up and hands immediately washed if chemicals get onto the skin. Burning reactions are covered in this unit. Pupils should be warned ofthe dangers of handling hot objects. Teachers must ensure that pupils know how to use a Bunsen burner and how to heat substances.

To make good progress, pupils starting this unitneed to understand: • that gases are materials• that some changes are reversible but others

are not• that acids are neutralised by alkalis.➞ Transition quiz for unit F

F1Lesson planning

guideChanging materials


Learning outcomes

Most pupils will … Some pupils, making less progress will … Some pupils, making moreprogress will …

• learn that a change in temperature, a flame, a colourchange, bubbles, a precipitate, or a substance beingused up are all indications of a chemical change

• learn the meaning of the words ‘reactant’ and‘product’.

• learn that a change in temperature, a flame, acolour change, bubbles, a precipitate, or asubstance being used up are all indications of achemical change.

• learn to construct a wordequation.

Learning objectivesi The difference between physical and chemical changes.ii Chemical changes involve chemical reactions and mean that new substances are made.iii The meaning of ‘chemical reaction’, ‘reactants’ and ‘products’.iv Chemical reactions can be represented by word equations. (red only)

Scientific enquiryv Make observations of chemical reactions. (Framework YTO Sc1 7d part)vi Generalise from those observations. (Framework YTO Sc1 7g)

Suggested alternative starter activities (5–10 minutes)

Introduce the unit Share learning objectives Brainstorming Capture interest (1) Capture interest (2)

Unit map for Simplechemical reactions.

• Find out about the many chemicalchanges that take place around us everyday.

• Be able to tell when a chemical reactionoccurs.

• Investigate the reaction of differentmetals with an acid. (Sc1)

To review chemicalchanges that occurin everyday life.

Burn paper and cook anegg to review theproduction of newsubstances duringchemical reactions.

Show photos/video clipsof an explosion and anarticle rusting.Catalyst InteractivePresentations 1

Suggested alternative main activitiesActivity Learning

objectivesee above

Description Approx.timing

Target group

C H E S

Textbook F1 i, ii, iii andiv

Teacher-led explanation and questioning OR pupils work individually, inpairs or in small groups through the in-text questions and then ontothe end-of-spread questions if time allows.

20 min R/G G R S

Activity F1aPractical

ii and v Seeing chemical reactions Pupils record observations of a series ofchemical reactions.

20 min ✓ ✓

Activity F1bPractical

v and vi Reactants and products Activity F1a is a prerequisite. Pupils work inpairs or trios to discuss three of the reactions in Activity F1a in moredetail and construct word equations.

20 min ✓

Suggested alternative plenary activities (5–10 minutes)Review learning Sharing responses Group feedback Word game Looking aheadPupils classify a range of examplesas representing physical orchemical change.

In groups, pupils sharetheir observationsfrom Activity F1a.

Pupils identify reactants andproducts in descriptions ofreactions.

Pupils match wordsand definitions.

Pupils suggest what evidencethey would need to collect tosee if acids react with metals.

Key wordsphysical change, reversible change, chemical change, irreversible change, chemical reaction,products, reactants, red only: word equations

Out-of-lesson learningHomework F1Textbook F1 end-of-spread questions

F2Lesson planning

guideAcids and metals


Learning outcomes

Most pupils will … Some pupils, making less progress will … Some pupils, making more progress will …

• know that most acids react with metalto make hydrogen

• know that metals corrode because ofchemical reactions

• know that the test for hydrogen is asqueaky pop with a lighted splint

• use this knowledge to make predictionsand identify anomalous results.

• know that the test for hydrogen is a squeakypop with a lighted splint

• know that acids react with metals to makehydrogen.

• also be able to work out the other product of thereactions.

Learning objectivesi Metals react with acid to make hydrogen.ii Carry out the test for hydrogen.iii Metals corrode because of chemical reactions.

Scientific enquiryiv Make observations. (Framework YTO Sc1 7d)v Generalise from those observations. (Framework YTO Sc1 7g)vi Investigate reacting metals with acid. (Framework YTO Sc1 7b, c, d, e, g)


Recap last lesson Share learning objectives Capture interest (1) Capture interest (2) Capture interest (3)

Pupils classifychanges as physicalor chemical changes.

• Find out how metals react withdilute acids.

• Be able to test for hydrogen gas.

Demo cleaning a coinusing acid.

Demo burning ofhydrogen gas.

Show a video clip of theairship Hindenburg explodinginto flames.Catalyst InteractivePresentations 1


objectivesee above


Target group

C H E S

Textbook F2 i, ii and iii Teacher-led explanation and questioning OR pupils work individually, inpairs or in small groups through the in-text questions and then ontothe end-of-spread questions if time allows.

20 min R/G G R S


i, ii, iii andiv

Reaction of magnesium and hydrochloric acid Demo of reaction ofmagnesium and hydrochloric acid, including demonstration of the testfor hydrogen. Pupils then carry out the reaction for themselves andanswer questions on the activity sheets.

40 min ✓ (✓ )

Activity F2bPractical

iv, v and vi Reacting metals with acids Pupils carry out a short investigation intothe reaction of metals with acid.

50 min ✓ ✓

Suggested alternative plenary activities (5–10 minutes)

Review learning Sharing responses Group feedback Word game Looking ahead

Pupils write a general rule tosummarise the pattern they haveobserved.

Whole-class discussion ofresponses to Activity F2a.

In groups, pupils discusstheir answers to ActivityF2b.

A quick quiz game. Pupils suggest whydentists tend to use goldor mercury for fillings.

Key wordshydrogen, corrosion, neutralisation, red only: sulphates


F3Lesson planning

guideAcids and carbonates


Learning outcomes


• know that acids react with carbonatesto make carbon dioxide

• know that the test for carbon dioxide isthat it turns limewater milky.

• know that the test for carbon dioxide is that itturns limewater milky.

• also be able to work out the other product of thereactions.

Learning objectivesi Carbonates react with acid to make carbon dioxide.ii Carry out the test for carbon dioxide.

Scientific enquiryiii Pupils make observations. (Framework YTO 7d)iv Pupils generalise from those observations. (Framework YTO 7g)


Recap last lesson Share learning objectives Problem solving Capture interest (1) Capture interest (2)

Pupils completesentences about acidsreacting with metals.

• Find out how carbonates react withacids.

• Be able to test for carbon dioxidegas using limewater. (Sc1)

Demo that carbondioxide is heavierthan air.

Demo the frothing ofcarbonated mineral wateror soft drink.

Demo the vigorous reactionof powdered sodiumcarbonate and hydrochloricacid.


objectivesee above


Target group

C H E S

Textbook F3 i and ii Teacher-led explanation and questioning OR pupils work individually, inpairs or in small groups through the in-text questions and then ontothe end-of-spread questions if time allows.

20 min R/G G R S


i, ii and iii Reaction of calcium carbonate with hydrochloric acid Demo ofreaction of hydrochloric acid with calcium carbonate, including using adelivery tube to bubble the gas through limewater. Pupils then carryout the reaction for themselves and answer questions on the activitysheets.

30 min ✓ (✓ )

Activity F3bPaper

i, ii and iv Two colourless gases Comparing carbon dioxide and hydrogen. 15 min ✓ (✓ )

Suggested alternative plenary activities (5–10 minutes)Review learning Sharing responses Group feedback Word game Looking aheadPupils write a general ruleto summarise the patternthey have observed.

In groups, share responsesto Activity F3a.

Whole-class discussion ofanswers to Activity F3b.

Check progress by playingloop game with key wordsfrom unit so far.

Pupils suggest otherreactions in which carbondioxide gas is produced.

Key wordscarbon dioxide, limewater, carbonates, neutralisation, red only: acid rain


F4Lesson planning

guideFirefighting


Learning outcomes


• learn that fuel, oxygen and some energyare needed to start burning

• realise that removing one of these canstop a fire

• realise that substances burn morevigorously in pure oxygen than airbecause air is only 20% oxygen

• understand that burning is a chemicalreaction

• learn that combustion is another wordfor burning.

• know that fuel, oxygen and some energy areneeded to start burning

• realise that removing one of these can stop afire.

• also use that knowledge of burning to discussstrategies for firefighting.

Learning objectivesi Burning reactions need oxygen as a reactant.ii Combustion is another word for burning reactions.iii The difference between burning reactions in air and in oxygen.iv All burning reactions give out energy.v A fire triangle reminds us of the three things needed to start a fire and helps us explain how to put out a fire.

Scientific enquiryvi Pupils make observations. (Framework YTO Sc1 7d)vii Pupils use their scientific knowledge in explanations. (Framework YTO Sc1 7g)


Recap last lesson Share learning objectives Brainstorming Problem solving Capture interest

Verbal quiz on thereaction of carbonateswith acids.

• Find out the difference betweenburning in air and in oxygen.

• Be able to work out the bestmaterial to put out a fire. (Sc1)

What safety precautionsshould we take whenburning things?

Pupils design hazardwarning symbols forcombustion.

Show a video clip of foambeing used to put out a fire.Catalyst InteractivePresentations 1


objectivesee above


Target group

C H E S

Textbook F4 i, ii, iii, ivand v

Teacher-led explanation and questioning OR pupils work individually, in pairsor in small groups through the in-text questions and then onto the end-of-spread questions if time allows.

20 min R/G G R S

Activity F4aPaper

i and ii Burning and energy Introduction of the scientific term energy.Demonstration of hydrogen balloon exploding (and, if wanted, magnesiumburning and a lighter being lit) followed by class discussion or activity sheetF4a.

10 min ✓

Activity F4b Practical

i and v Putting fires out Pupils carry out an experiment to discover the bestmaterial for putting out a fire.

15 min ✓ ✓

Activity F4cPractical

vi and vii Burning candles Pupils watch a demonstration of a lighted candle floatingon water and explain what happens.

10 min ✓

Key wordsoxygen, fuel, combustion, fire triangle

Out-of-lesson learningHomework F4Textbook F4 end-of-spread questionsVisit a fire station to see fire prevention display

Suggested alternative plenary activities (5–10 minutes)Review learning Sharing responses Group feedback Word game Looking aheadPupils create fire triangleposter with advice forelderly residents.

Whole-class discussionof responses to ActivityF4a.

In groups, pupils discusstheir responses to ActivityF4b.

Play ‘Mastermind’. Pupils suggest what tests they wouldcarry out to identify the presence ofwater.

F4Lesson planning

guideInvestigate: How much air does aburning candle need?


Learning outcomes


• carry out steps in an investigation,using their ideas about burning in theirexplanation.

• with help, carry out all steps in aninvestigation and relate their ideas aboutburning to their results.

• also use their ideas about burning to explaintheir prediction and explain any anomalousresults.

Learning objectivesi Use ideas about burning in a full investigation into burning candles.

Scientific enquiryii Make predictions of possible outcomes. (Framework YTO Sc1 7b)iii Identify and control the key factors that are relevant to the investigation. (Framework YTO Sc1 7c)iv Select and use appropriate equipment and make observations. (Framework YTO Sc1 7d)v Use repeat measurements to reduce error and check reliability. (Framework YTO Sc1 7e)vi Present and interpret experimental results. (Framework YTO Sc1 7f)vii Describe and explain what their results show and evaluate the strength of evidence. (Framework YTO Sc1 7g, 7h)


Setting the context Introduce the apparatus Safety Brainstorming (1) Brainstorming (2)

Pupils discuss ideas aboutburning: what is neededfor burning and what isproduced.

Demonstrate how to set upand use the apparatus for theinvestigation.

Pupils discuss what thehazards are for theinvestigation.

The variables in theinvestigation. Leadinto using differentvolumes of air.

Brainstorm the need for a fairtest.

InvestigationActivity Learning

objectivessee above


Target group

C H E S

Activity F4dPaper

i, ii and iii How much air does a burning candle need? Planning Pupils plan aninvestigation based on the demonstration in Activity F4c, in which thevolume of air is varied.

20 min ✓ ✓

Activity F4ePractical

iv, v and vi How much air does a burning candle need? Obtaining evidencePupils carry out the plan they made in Activity F4d. They plot theirresults in a graph.

20 min ✓ ✓

Activity F4fDiscussion

vii How much air does a burning candle need? Considering andevaluating the evidence Pupils look at the results from their experimentand the graph they drew. They decide whether the prediction they madein Activity F4d was correct.

20 min ✓ ✓

Suggested alternative plenary activities (5–10 minutes)Review learning Group feedback Analysing EvaluatingTeacher-led discussion of theplanning procedure.

Pupils share theirpredictions.

Teacher-led discussion of thedata collected.

Teacher-led discussion on how reliable thedata is and how it could be improved.

F5Lesson planning

guideBurning changes


Learning outcomes


• know that substances react with oxygento make oxides

• be able to represent such reactions asword equations.

• know that substances react with oxygen tomake oxides

• be able to recognise some word equations asburning reactions.

• also begin to write word equations fromobserved or described reactions

• know the product of burning hydrocarbons.

Learning objectivesi Chemical reactions with oxygen make oxides.ii Represent chemical reactions by word equations.iii When hydrocarbons burn they produce both carbon dioxide and water. (red only)

Scientific enquiryiv Pupils make observations. (Framework YTO Sc1 7d)v Pupils generalise from those observations. (Framework YTO Sc1 7g)



Pupils considerwhat is needed forburning.

• Find out what the products ofcombustion are.

• Be able to write word equations forsome burning reactions.

• Find out what happens when threemetals are burnt in air. (Sc1)

Pupils discuss trueand false ideasabout burning.

Show video clips ofphosphorus and sodiumbeing burned in air and inoxygen.Catalyst InteractivePresentations 1

Show a video clip of thespace shuttle taking off.Catalyst InteractivePresentations 1


objectivessee above


Target group

C H E S

Textbook F5 i, ii, and iii Teacher-led explanation and questioning OR pupils work individually, inpairs or in small groups through the in-text questions and then ontothe end-of-spread questions if time allows.

20 min R/G G R S


i, ii, iv and v Making oxides Demo of burning magnesium, carbon and sulphur in air andin oxygen. Pupils then record their observations and answer questions.

30 min ✓ ✓ (✓ )

Activity F5bPaper

i, ii and v Chemical reactions Provide pupils with a series of cards showing wordsor phrases about chemical reactions and ask them to group them.

15 min ✓

Activity F5cCatalyst InteractivePresentations 1

i Support animation for pupils identified as having problems withremembering that acid + carbonate ➞ carbon dioxide, acid + metal ➞ hydrogen and burning (in oxygen) ➞ oxides.

10 min ✓

Activity F5dCatalyst InteractivePresentations 1

iii Support activity using drag and drop activity with immediate feedbackfor pupils identified as having problems with word equations.

10 min ✓

Suggested alternative plenary activities (5–10 minutes)Review learning Sharing responses Group feedback Word games Looking backPupils summarise in asentence what happenswhen a substance burns.

Pupils discuss observationsfrom Activity F5a.

Pupils compare wordequations and discussconventions.

Match halves of wordequations about burningmetals and fuels.

Pupils revise andconsolidate knowledgefrom the unit.

Key wordscharcoal, word equation, reactants, products, oxides, hydrocarbons, redonly: methane, toxic, lethal


F6Lesson planning

guideGetting hotter – Think aboutrelationships between variables


Learning outcomes


• recognise the relationship between theinput and outcome variables fromsecondary data.

• with help, recognise the relationship betweenthe input and outcome variables fromsecondary data.

• also interpret relationships between variablesusing graphs.

Learning objectivesi Scientists use models to test ideas. ii Relationships between variables.The structure of this lesson is based around the CASE approach. The starter activities and main activity F6a give concrete preparation. The textbook movesaway from the concrete towards a challenging situation, where pupils need to think. The extended plenary gives pupils time to discuss what they havelearnt, to negotiate a method to commit to paper and express their ideas verbally to the rest of the class.

Scientific enquiryiii Use scientific knowledge to decide how ideas and questions can be tested; make predictions of possible outcomes. (Framework YTO Sc1 7b)


Bridging to the unit Setting the context Concrete preparation (1) Concrete preparation (2)

Link to the part of the unitabout burning and theproducts of burning.

The gases produced in burning could becausing the greenhouse effect. Look at thevariables: temperature and carbon dioxide.

Class discussion andexplanation of how a normalgreenhouse works.

Pupils look at newspaper articlesabout global warming.

Suggested main activitiesActivity Learning

objectivesee above


Target group

C H E S

Textbook F6 i, ii and iii Teacher-led explanation and questioning OR pupils work individually, inpairs or in small groups through the in-text questions and then ontothe end-of-spread questions if time allows.

30 min R/G G R S


i and iii Burning fossil fuels Activity to provide concrete preparation for thethinking lesson.

20 min ✓

Suggested alternative plenary activities (5–10 minutes)Group feedback Bridging to other topicsIn groups, pupils discuss why they think scientists need to test theirideas and models.

Ask pupils to think of instances where relationships between variablescould be used in other contexts. Many investigations will need pupils tobe able to find relationships in data.

Key wordsgreenhouse effect, relationship, red only: model

Out-of-lesson learningTextbook F6 end-of-spread questions

F1

© Harcourt Education Ltd 2003 Catalyst 1This worksheet may have been altered from the original on the CD-ROM.

StartersChanging materials

Sheet 1 of 1

Introduce the unit● Either draw the outline of the unit map on the board

then ask pupils to give you words to add, saying whereto add them. Suggest some words yourself whennecessary to keep pupils on the right track.

● Or give out the unit map and ask pupils to work ingroups deciding how to add the listed words to thediagram. Then go through it on the board as eachgroup gives suggestions.

Share learning objectives● Ask pupils to write a list of FAQs they would put on a

website telling people about how materials change.Collect suggestions as a whole-class activity, steeringpupils towards those related to the objectives. Concludeby highlighting the questions you want them to be ableto answer at the end of the lesson.

Brainstorming● Organise pupils in small groups to spend 2 minutes

suggesting chemical changes in everyday life.

● Take one suggestion from each group to discuss thequestions opposite with the class.

Capture interest (1)● Set fire to a piece of paper and let it burn completely.

● Use the questions opposite to revise the idea ofreversible and irreversible changes.

● Crack an egg and drop the white and yolk into boilingwater in a beaker. After a couple of minutes remove thecooked egg. Let pupils see the changes.

● Use the questions opposite to revise the idea ofreversible and irreversible changes and introduce theidea of a chemical change.

Capture interest (2)● Show a series of photos/video clips of a fast change

(explosion) and a slow change (iron rusting).

● Ask pupils for their observations in a class discussion.Are these changes reversible? Explain that these areboth chemical changes.


Unit map for Simplechemical reactions.

● Find out about the many chemicalchanges that take place around us every day.

● Be able to tell when a chemicalreaction occurs.

● Investigate the reaction of different metals with an acid.(Sc1)

To review chemicalchanges that occur ineveryday life.

Burn paper and cookan egg to review theproduction of newsubstances duringchemical reactions.

Show photos/videoclips of an explosionand an article rusting.Catalyst InteractivePresentations 1

Introduce the unit Share learning objectives Brainstorming Capture interest (1) Capture interest (2)

➔ Unit map

➔ Technician sheetQuestionsCan ash be turned back into paper?How is ash different from paper?

QuestionsIs a new substance produced?Is the change irreversible?Is it a chemical change?

QuestionsCan cooked egg be turned back into rawegg?How is cooked egg different from raw egg?

➔ Catalyst Interactive Presentations 1

© Harcourt Education Ltd 2003 Catalyst 1This worksheet may have been altered from the original on the CD-ROM. Sheet 1 of 1

F Unit mapSimple chemical reactions

carbon dioxidecharcoalchemical reactioncombustioncorrosionenergyfire trianglefuelgreenhouse effecthydrocarbons Rhydrogen

irreversiblelimewatermethane Rneutralisationoxidesoxygenproductsreactantsreversibleword equations

Copy the unit map and use these words to help you complete it. You may add words of your own too.

�

Chemicalreactions

Physical and chemical changes Acids and metals

Acids andcarbonates

Burning

Firefighting


Capture interest (1)

Technician sheetSupply the following for a demonstration:

● paper for burning

● heatproof mat

● tongs

● Bunsen burner

● hen’s egg

● 400 cm3 beaker

● tripod and gauze.

F1 StartersChanging materials

F2


StartersAcids and metals

Sheet 1 of 1

Recap last lesson● Show the list of physical and chemical changes on an

OHT. Ask pupils to sort them into two lists: physicalchanges (not producing a new substance) and chemicalchanges (producing a new substance).

● When pupils have completed their lists, ask for a show ofhands for each change to get an idea which ones may havecaused confusion.

● Discuss reasons for putting these in one list or the other.


website telling people about how metals react with acids.Collect suggestions as a whole-class activity, steeringpupils towards those related to the objectives. Conclude byhighlighting the questions you want them to be able toanswer at the end of the lesson.

Capture interest (1)● Take a dirty coin and drop it into a little concentrated

hydrochloric acid (wear eye protection).

● After a few seconds use plastic forceps to remove the coinand wash it. Let pupils see that the appearance of the coinhas changed.

● Introduce the idea of the metal reacting with the acid andthat a gas is produced.

Capture interest (2)● Fill a balloon with hydrogen from a cylinder and tether it

to a clamp and stand surrounded by safety screens.

● Introduce a lighted taper taped to the end of a metal rodbetween two of the screens to light the hydrogen gas inthe balloon.

● Let the pupils note that hydrogen gas burns noisily, andlead them to suggest that this could allow them to identifythe gas as hydrogen.

Capture interest (3)● Show a video clip of the airship Hindenburg exploding into

flames as it came to land in New York.

● Then lead a class discussion about the flammability ofhydrogen and why helium is now used in airships.


Pupils classify changesas physical or chemicalchanges.

● Find out how metalsreact with dilute acids.

● Be able to test forhydrogen gas. (Sc1)

Demo cleaning a coinusing acid.

Demo burning of hydrogengas.

Show a video clip of theairship Hindenburgexploding into flames.Catalyst InteractivePresentations 1

Recap last lesson Share learning Capture interest (1) Capture interest (2) Capture interest (3)objectives

➔ Pupil sheet


➔ Technician sheet



Recap last lesson

melting ice into water

burning gas on a cooker

an iron nail rusting

dissolving sugar in tea

wood burning on a fire

grinding coffee beans to powder

F2 StartersAcids and metals




● a dirty coin e.g. a 2p piece

● a 100 cm3 beaker

● concentrated hydrochloric acid

● plastic forceps

● eye protection.



�



● a balloon

● a hydrogen cylinder

● a clamp and stand

● string or thread

● three safety screens

● a taper

● a metal rod e.g. from a stand

● means of lighting the taper

● eye protection.


F3


StartersAcids and carbonates

Sheet 1 of 1

Recap last lesson● As they enter the room, hand each pupil the pupil

sheet. They begin immediately.

● When all pupils are seated and organised, askindividual pupils to read out their completed sentences.Correct and discuss any mistakes.


website telling people about how carbonates react withacids. Collect suggestions as a whole-class activity,steering pupils towards those related to the objectives.Conclude by highlighting the questions you want themto be able to answer at the end of the lesson.

Problem solving● Collect a boiling tube of carbon dioxide and show

pupils that plunging a burning splint into it puts outthe splint.

● Emphasise that this is not a reliable test for carbondioxide as several gases will put out a lighted splint.Pupils will learn another test for carbon dioxide.

● Tell pupils that carbon dioxide is heavier than air. Askthem to work in groups to decide how they coulddemonstrate this, then report back. If the idea ofpouring the gas onto a lighted splint is not suggested,then describe this idea.

● Demonstrate pouring carbon dioxide onto a lightedsplint, similar to pouring a liquid. The splint goes out.

Capture interest (1)● Shake a bottle of sparkling mineral water or carbonated

soft drink and then quickly open the top. A froth ofcarbon dioxide and liquid will be ejected.

● Ask pupils what is happening and why. Explain thatcarbon dioxide gas causes the bubbles.

Capture interest (2)● Add about 5 g (pre-weighed) sodium carbonate to a

beaker three-quarters full of dilute hydrochloric acid.

● They react vigorously; froth will overflow the beaker.Explain that a gas is produced in some reactions.


Pupils completesentences about acidsreacting with metals.

● Find out howcarbonates react withacids.

● Be able to test forcarbon dioxide gasusing limewater. (Sc1)

Demo that carbon dioxideis heavier than air.

Demo the frothing ofcarbonated mineral wateror soft drink.

Demo the vigorous reactionof powdered sodiumcarbonate and hydrochloricacid.

Recap last lesson Share learning Problem solving Capture interest (1) Capture interest (2)objectives

➔ Pupil sheet


Equipmenta bottle of carbonated drink



Recap last lessonComplete these paragraphs about acids reacting with metals.

Most metals react with acids to produce ...................................... gas.

This gas can be tested by using a ...................................... splint.

In a positive test the gas will ...................................... with a ...................................... sound.

The gas produced is ...................................... than air and so will

...................................... from a test tube. To keep the gas inside the test tube,

you can put a ...................................... over the end.

F3 StartersAcids and carbonates


F3 Starters

�

Acids and carbonates

Recap last lessonComplete these paragraphs about acids reacting with metals.

Most metals react with acids to produce ...................................... gas.

This gas can be tested by using a ...................................... splint.

In a positive test the gas will ...................................... with a ...................................... sound.

The gas produced is ...................................... than air and so will

...................................... from a test tube. To keep the gas inside the test tube,

you can put a ...................................... over the end.


Problem solving


● a 250 cm3 bottle of dilute (1 mol/dm3) hydrochloric acid

● marble chips

● two boiling tubes

● a delivery tube and stopper to fit a boiling tube

● wooden splints

● a Bunsen burner and heatproof mat.

F3 StartersAcids and carbonates

F3 Starters

�

Acids and carbonates



● sodium carbonate powder

● a spatula

● an electronic balance

● two 100 cm3 beakers

● a 250 cm3 bottle of dilute hydrochloric acid (1 mol/dm3)

● paper towels.


F4


StartersFirefighting

Sheet 1 of 1

Recap last lesson● Have all pupils standing. Ask each pupil in turn a

question from the teacher sheet about carbonates andacids. If they answer correctly they can sit down.

● Differentiate the difficulty of questions to matchabilities of pupils, so that all pupils will quickly beseated. The same question may be used more than once.


website telling people about combustion andfirefighting. Collect suggestions as a whole-classactivity, steering pupils towards those related to theobjectives. Conclude by highlighting the questions youwant them to be able to answer at the end of thelesson.

Brainstorming● Ask what safety precautions should be taken when

burning materials.

● Allow pupils to discuss this in small groups, then reportback. List suggestions on the board.

Problem solving● Tell the class that containers of flammable materials

carry a hazard warning sign.

● Ask pupils to work in pairs to design a hazard warningsign to be put on a bottle of flammable material such aspetrol.

● Show pupils the ‘real’ hazard symbol for flammablematerials. Discuss with the class the need for hazardsymbols to be simple and to clearly show the hazardinvolved.

● Display the best designs around the laboratory,together with the ‘real’ symbol for comparison.

Capture interest● Show pupils a video clip of foam being used to put out

a fire (such as an aircraft fire).

● Ask pupils what the foam is doing. Be careful not tocover what is in the lesson.


Verbal quiz on thereaction of carbonateswith acids.

● Find out the differencebetween burning in airand in oxygen.

● Be able to work out thebest material to put out a fire. (Sc1)

What safety precautionsshould we take whenburning things?

Pupils design hazardwarning symbols forcombustion.

Show a video clip of foambeing used to put out afire.Catalyst InteractivePresentations 1

Recap last lesson Share learning Brainstorming Problem solving Capture interestobjectives

➔ Teacher sheet

Equipment‘flammable’ hazard symbol



Recap last lesson

Teacher sheet

Easier1 Give me the names of a carbonate and an acid that react together.

2 What do you see when a carbonate reacts with an acid?

3 What is the name of the gas given off when a carbonate reactswith an acid?

4 What gives the fizz in cola and lemonade?

5 What is the test for carbon dioxide?

Harder1 How do you know that a chemical reaction has taken place when a

carbonate is added to an acid?

2 When different carbonates and different acids are reacted together,what are the similarities and differences?

3 How is the gas produced from calcium carbonate and an aciddifferent from the gas produced from a metal and an acid?

4 Other than carbon dioxide, what else is made when a carbonatereacts with hydrochloric acid?

5 What is a general word equation for the reaction of a carbonateand an acid?

F4 StartersFirefighting

F4


StartersInvestigate: How much airdoes a burning candle use?

Sheet 1 of 1

Setting the context● Write the questions opposite on the board. Ask pupils

to work in pairs to answer them.

● Ask pairs for their answers to initiate class discussion.

Introduce the apparatus● Ask pupils to work in pairs to design apparatus that can

be used to investigate how much air is used up byburning a candle.

● Then show them the apparatus in Activity F4def anddemonstrate its use.

Safety● Ask pupils to work in pairs to list the hazards involved

in this investigation.

● Pupils then decide how to minimise the dangerpresented by each hazard.

● Groups report back to a class discussion during which afinal set of safety procedures is listed on the board.

Brainstorming (1)● Ask pupils to discuss in groups what the variables are in

the investigation.

● Ask them to decide what variable should be changed(input variable) and what should be measured duringthe investigation (outcome variable).

● Ask individual pupils for their ideas. Lead them tosuggest using different volumes of air. Use classdiscussion to finalise details of the two dependentvariables.

Brainstorming (2)● Ask pupils to work in groups to consider what needs to

be done to make this a fair test.

● Use answers from individual pupils to initiate classdiscussion about fair testing and reliability of results.


Pupils discuss ideasabout burning: what isneeded for burning andwhat is produced.

Demonstrate how to set upand use the apparatus forthe investigation.

Pupils discuss what thehazards are for theinvestigation.

The variables in theinvestigation. Lead intousing different volumes ofair.

Brainstorm the need for afair test.

Setting the context Introduce the Safety Brainstorming (1) Brainstorming (2)apparatus

QuestionsWhat is needed for a substance to burn?What is produced when a substance burns?

F5


StartersBurning changes

Sheet 1 of 1

Recap last lesson● Ask pupils to work in pairs to decide what is necessary for

a material to burn. They report back their ideas, which arewritten on the board.

● Have a class discussion about which ideas are correct,ending up with three things that are needed: acombustible material, oxygen and a hightemperature/enough energy.

● Pupils then decide which materials from the list oppositewill burn. (Pupils may need to be shown a crucible.)


website telling people about burning reactions. Collectsuggestions as a whole-class activity, steering pupilstowards those related to the objectives. Conclude byhighlighting the questions you want them to be able toanswer at the end of the lesson.

Problem solving● Ask pupils to work in groups of three or four to brainstorm

true and false ideas about burning (the teacher sheetprovides some ideas). They report back their ideas, whichare written on the board.

● Go through the ideas in turn and ask the class to decidewhether each is true or false.

● Add some ideas of your own to the list and ask pupils todecide whether they are true or false.

Capture interest (1)● Show a video clip of phosphorus and sodium being

burned in air and in oxygen. Highlight for pupils howthey burn differently and why.

Capture interest (2)● Show a video clip of the space shuttle taking off. Ask what

fuel the space shuttle uses. Ask what is in the tanks attachedto it. Lead pupils to the idea that the shuttle has to take bothfuel (hydrogen) and oxygen for the fuel to react with.

● Ask why an aeroplane does not need to carry oxygen toreact with its fuel.


Pupils consider what isneeded for burning.

● Find out what the products ofcombustion are.

● Be able to write word equations forsome burning reactions.

● Find out what happens when threemetals are burnt in air. (Sc1)

Pupils discuss trueand false ideas aboutburning.

Show video clips ofphosphorus and sodiumbeing burned in air andin oxygen.Catalyst InteractivePresentations 1

Show a video clip ofthe space shuttletaking off.Catalyst InteractivePresentations 1


List1 wood held in a Bunsen burner flame

at 500 °C2 wood heated to 500 °C in a sealed

tube3 wood heated to 100 °C in a crucible4 an iron nail held in a Bunsen burner

flame at 500 °C


➔ Teacher sheet



Problem solving

Teacher sheetBelow are some statements which pupils may come up with, orwhich could be added to pupils’ ideas.

True or false statements about burning1 When something burns it gets lighter. (false)

2 Burning always uses up oxygen. (true)

3 Burning always releases carbon dioxide into the air. (false)

4 Burning always releases heat energy. (true)

5 A substance will not burn until it reaches its ignition temperature. (true)

6 Metals do not burn. (false)

7 Because there is no oxygen in space, the space shuttle takes its own supply of oxygen to burn its fuel. (true)

8 Candle wax turns into a gas before it burns. (true)

9 If you lower the temperature of a burning substance, it will stop burning. (true)

10 Water will always put out a fire, whatever is burning. (false)

F5 StartersBurning changes

F6


StartersGetting hotter – Think about

Sheet 1 of 1

Bridging to the unit● Talk to pupils about how the fuels we burn contain

carbon. Coal is made mainly of carbon. Natural gas andoil also contain carbon, as does wood.

● Ask pupils to suggest the products formed when each ofthese fuels burns. Begin with coal since this forms onlyone product on burning. Lead them to conclude thatburning all these fuels produces carbon dioxide.

● Ask for suggestions of situations where we burndifferent fuels, both at home and in industry andtransport. Build up a list on the board. Conclude thatin all these places and situations carbon dioxide isproduced by the activities of people.

Setting the context● Explain that carbon dioxide traps energy from the Sun

in the Earth’s atmosphere. The atmosphere todaycontains about 0.4% carbon dioxide.

● Ask pupils to consider the questions opposite. Then askindividual pupils for their answers.

● Lead into a class discussion about the connectionbetween the two dependent variables of temperatureand the carbon dioxide content of the atmosphere.

Concrete preparation (1)● Ask pupils the questions on the teacher sheet.

● Use the ideas generated by pupils to explain how agreenhouse works.

● Introduce additional ideas as necessary to explain howless heat escapes from a greenhouse than enters it.

Concrete preparation (2)● Prepare for this activity by asking pupils to bring in

magazine or newspaper articles about global warming,floods, hurricanes, droughts, etc. Have a supply readyyourself.

● During a class discussion, look at some of the articles.Ask pupils to try and answer the questions on theteacher sheet.


Link to the part of the unit aboutburning and the products ofburning.

The gases produced in burningcould be causing the greenhouseeffect. Look at the variables:temperature and carbon dioxide.

Class discussion and explanationof how a normal greenhouseworks.

Pupils look at newspaper articlesabout global warming.

➔ Teacher sheet

QuestionsWhat would the Earth be like if there wasno carbon dioxide in the atmosphere?

What would the Earth be like if there was10% carbon dioxide in the atmosphere?

Equipmentmagazine and newspaper articles aboutglobal warming➔ Teacher sheet

Bridging to the unit Setting the context Concrete preparation (1) Concrete preparation (2)


Concrete preparation (1)

Teacher sheet1 What is a greenhouse for?

2 Why do plants grow quicker in a greenhouse?

3 Where does the heat energy in a greenhouse come from?

4 How does heat energy escape from a greenhouse?

5 Why is it warmer inside a greenhouse than outside?

F6 StartersGetting hotter

F6 Starters

�

Concrete preparation (2)

Teacher sheet1 Do extreme weather conditions seem to be getting more

frequent?

2 What could be an explanation for this?

3 What is global warming?

4 How can global warming cause one place to be drier and anotherto be wetter?

Getting hotter


Sheet 1 of 1© Harcourt Education Ltd 2003 Catalyst 1This worksheet may have been altered from the original on the CD-ROM.

Running the activityPupils work in small groups. They are provided with a match to strike, andlabelled tubes containing reagents in a test tube rack. They strike the match, andstart each reaction by tipping the contents of one tube into another. They recordtheir observations.

Core: Pupils carry out the reactions listed on the sheet and prepare their owntable.

Help: A fill-in results table is provided. This may be used in addition to the Coresheet for pupils who need it.

Expected outcomesPupils make observations of the changes that occur with a chemical reaction. In Ea precipitate appears, but pupils will probably not know this term, instead theymay observe that the solution goes cloudy.

B Fizzing. If hydrochloric acid is in excess the calcium carbonate may disappear.A colourless gas and a colourless solution are produced.

C The colour of indicator changes from red to blue or purple. An alkalinesolution is produced.

D The blue colour of copper sulphate disappears. Grey zinc granules becomecoated with red-brown solid. A colourless solution and a red-brown solid areproduced.

E A yellow precipitate is formed. Colourless solutions change to a cloudy yellowappearance. A fine yellow solid is produced in a colourless solution.

F Vigorous fizzing. The magnesium ribbon gets smaller or disappears. Heat isgiven out. A gas and a colourless solution are produced.

PitfallsMake sure that the amounts of nitric acid and sodium hydroxide are such that thefinal product changes the colour of the indicator. Make sure that there are enoughzinc granules and a low enough concentration of copper sulphate solution so thatthe blue colour vanishes.

Safety notesPupils should wear eye protection. Remind them to wipe up spills and wash theirhands if they get chemicals on their skin. They should take care with acids andalkalis (the lowest concentrations that work effectively should be used). Coppercompounds are harmful.

F1aTeacher

activity notesSeeing chemical reactions

Practical Pupils carry out a series of test-tube chemical reactions, recording their observations. Core, Help

Type Purpose Differentiation


Equipment For each group:● a few matches and a box for striking with a heatproof mat, labelled A● a test tube rack containing the following in separate test tubes and labelled

with the contents and the letter:B hydrochloric acid and calcium carbonateC nitric acid with universal indicator and sodium hydroxide solutionD zinc (with a bung in the tube) and copper sulphate solutionE lead nitrate and potassium iodide

● F dilute sulphuric acid and magnesium

TipsUse approximately 2 cm3 of the solutions, a spatula full of calcium carbonate, afew pieces of zinc and 1–2 cm of magnesium ribbon. Use bench strength or loweracids and alkalis. Check that the amounts of nitric acid and sodium hydroxide aresuch that the indicator changes colour. Make sure that there are enough zincgranules and a low enough concentration of copper sulphate so that the bluecolour vanishes.

For your informationRunning the activityPupils work in small groups. They are provided with a match to strike, andlabelled tubes containing reagents in a test tube rack. They strike the match, andstart each reaction by tipping the contents of one tube into another. They recordtheir observations.

Core: Pupils carry out the reactions listed on the sheet and prepare their owntable.

Help: A fill-in results table is provided. This may be used in addition to the Coresheet for pupils who need it.

Expected outcomesPupils make observations of the changes that occur with a chemical reaction. In Ea precipitate appears, but pupils will probably not know this term, instead theymay observe that the solution goes cloudy.B Fizzing. If hydrochloric acid is in excess the calcium carbonate may disappear.

A colourless gas and a colourless solution are produced.C The colour of indicator changes from red to blue or purple. An alkaline

solution is produced.D The blue colour of copper sulphate disappears. Grey zinc granules become

coated with red-brown solid. A colourless solution and a red-brown solid areproduced.

E A yellow precipitate is formed. Colourless solutions change to a cloudy yellowappearance. A fine yellow solid is produced in a colourless solution.

F Vigorous fizzing. The magnesium ribbon gets smaller or disappears. Heat isgiven out. A gas and a colourless solution are produced.

Safety notesPupils should wear eye protection. Remind them to wipe up spills and wash theirhands if they get chemicals on their skin. They should take care with acids andalkalis (the lowest concentrations that work effectively should be used). Coppercompounds are harmful.

F1aTechnician

activity notesSeeing chemical reactions

Practical Pupils carry out a series of test-tube chemical reactions, recording their observations. Core, Help


Sheet 1 of 1

F1a


ActivityCore

Some chemical reactions happen without you noticing. But it ispossible to see some chemical reactions. In this activity you aregoing to observe six chemical reactions and record yourobservations.

Obtaining evidence and presenting the results1 Make a table with these headings. (Your teacher may give you a

table to fill in.)

2 Now carry out chemical reactions A to F below, filling in yourtable as you go. Write as much detail as you can in columns (2),(4) and (5) – these are your observations. The table below showsthe first reaction filled in.

A Burn a match.B Mix hydrochloric acid and calcium carbonate powder.C Take a test tube of nitric acid. It has universal indicator mixed

with it. Add sodium hydroxide solution.D Take a test tube of zinc pieces. Add copper sulphate solution.

Put a bung in and shake.E Take a test tube of lead nitrate solution. Add potassium iodide

solution.F Take a test tube of sulphuric acid and add a piece of

magnesium.

Seeing chemical reactions

(1) Chemical (2) Describe the (3) What did you (4) Describe what (5) Describe thereaction reactants do to start the happened products you

reaction? during the could see reaction



AA Burn a Wood: beige solid. We struck the We saw an orange Papery, black

match Oxygen in the match. flame. It was solid and smoke.

air: colourless hot. The wood

gas. turned black and

got smaller.

!

Wear eyeprotection.

Wipe up spills.Wash your

hands if you getchemicals on yourskin. Take care withacids and alkalis.Copper compounds are harmful.

Sheet 1 of 1

F1a


ActivityHelp

Presenting the results1 Record your observations in this table.

● In column (4) describe any changes you see. How does thecolour change? Is there any fizzing? Does it get warmer?Is a new product formed?

● In column (5) describe any products. What colour are they?Are they solid, liquid or gas? Is there a mixture?

Seeing chemical reactions



AA Burn a Wood: beige solid. We struck the We saw an orange Papery, blackmatch Oxygen in the match. flame. It was solid and smoke.

air: colourless hot. The woodgas. turned black and

got smaller.

B Mix hydrochloric Hydrochloric acid: We m.......................... We sawacid and calcium c.......................... the hydrochloric ......................................

carbonate powder. s.......................... . acid and calcium ......................................

Calcium carbonate: carbonate powder. ......................................

w..........................

p.......................... .

C Take a test tube Nitric acid with We added theof nitric acid. It has universal indicator: s..........................

universal indicator c.......................... h.......................... tomixed with it. s.......................... . the n..........................

Add sodium Sodium hydroxide: a..........................

hydroxide. c.......................... and u..........................

s.......................... . i.......................... .

D Take a test tube Zinc: g........................ We added theof zinc pieces. Add s.......................... c..........................

copper sulphate granules. Copper s..........................

solution. Put a bung sulphate: solution to thein and shake. b.......................... z.......................... .

s..........................

E Take a test tube of Lead nitrate: We addedlead nitrate solution. c.......................... p..........................

Add potassium s.......................... i..........................iodide solution. Potassium iodide: solution to the

c........................... l..........................s.......................... . n..........................

solution.

F Take a test tube Sulphuric acid: We added thesulphuric acid and c.......................... m.......................... toadd a piece of s.......................... the s.........................

magnesium. Magnesium: a.......................... .g..........................

s.......................... .


Running the activityPupils discuss in groups to identify from a list the reactants and products for reactions B, D and E from Activity F1a. They write a word equation for each reaction.

Other relevant materialActivity sheet F1a CoreSkill sheet 15: Word equations

Answershydrochloric acid � calcium carbonate → calcium chloride � carbon dioxide � water

zinc � copper sulphate → zinc sulphate � copper

lead nitrate � potassium iodide → lead iodide � potassium nitrate

F1bTeacher

activity notesReactants and products

Discussion Pupils write word equations for some of the reactions they observed in Activity F1a. Extension


3

12

Sheet 1 of 1

F1b


ActivityExtension

You are going to discuss chemical reactions B, D and E from Activity F1a. First you are going to identify the reactants and products. Then you will write out a word equation for each reaction. Word equations record what happened during the reaction.

The reactants The products● hydrochloric acid ● copper (a red-brown solid)● calcium carbonate ● carbon dioxide (a colourless gas)● zinc ● lead iodide (a yellow solid that does not dissolve)● copper sulphate ● calcium chloride (a soluble, colourless substance)● lead nitrate ● zinc sulphate (a soluble, colourless substance)● potassium iodide ● potassium nitrate (a soluble, colourless substance)

● water (a colourless liquid)

1 In your group, first discuss where to put the reactants and the products in each diagram below.

2 Then copy the diagrams and fill in the reactants and products. These diagrams are called word equations.

Reactants Products

B � _ � �

D � _ �

E � _ �

When you write word equations in future, you do not need to draw boxes around the reactants and products. But it is important to keep the two parts of the name together. For example, ‘zinc sulphate’ is very different from ‘zinc’.

Reactants and products

2

3

1


Running the activityFirst demonstrate the reaction, and show pupils how to test for hydrogen. Explainwhy it is necessary to use a bung to trap the hydrogen (to stop it floating away,because hydrogen is less dense than air). The pupils then carry out the reactionthemselves and carry out the test for hydrogen.

Core: Pupils copy and complete a results table for the test for hydrogen, andanswer questions about the reactions.

Extension: There are additional questions at the foot of the Core sheet askingpupils to write word equations, which can be cut off if not required.

Expected outcomesPupils will see the vigorous reaction between magnesium and acid again (whichthey have already met in Activity F1a) and will learn how to collect the hydrogengiven off in order to test it. They also experience the squeaky pop of hydrogenwith a lighted splint.

Safety notesPupils should wear eye protection. They should take care with the acid. The tubecan become hot. The reaction is vigorous and acid may spurt out of the tube.

Answers Core:

A gas was given off and the magnesium disappeared/got smaller. (Whetherthe magnesium completely disappears or not will depend on the length ofribbon supplied and the amount and strength of the acid.)

Hydrogen is a colourless gas with a lower density than air that explodes whenlit.

Extension

Because hydrogen has a lower density than air and will float away.

magnesium � hydrochloric acid → magnesium chloride � hydrogen

hydrogen � oxygen → water

F2aTeacher

activity notesReaction of magnesium andhydrochloric acid

Practical Pupils observe magnesium reacting with hydrochloric acid and learn how to test for Core (Extension)hydrogen.


3

1

2

4

5


EquipmentFor each group:● a test tube and rack● a bung● a few cm3 of dilute hydrochloric acid● 1–2 cm of magnesium ribbon● a splint● access to a Bunsen burner flame (or matches to light the splint)

For your information

Running the activityFirst demonstrate the reaction, and show pupils how to test for hydrogen. Explainwhy it is necessary to use a bung to trap the hydrogen (to stop it floating away,because hydrogen is less dense than air). The pupils then carry out the reactionthemselves and carry out the test for hydrogen.

Core: Pupils copy and complete a results table for the test for hydrogen, andanswer questions about the reactions.

Extension: There are additional questions at the foot of the Core sheet askingpupils to write word equations, which can be cut off if not required.

Expected outcomesPupils will see the vigorous reaction between magnesium and acid again (whichthey have already met in Activity F1a) and will learn how to collect the hydrogengiven off in order to test it. They also experience the squeaky pop of hydrogenwith a lighted splint.

Safety notesPupils should wear eye protection. They should take care with the acid. The tubecan become hot. The reaction is vigorous and acid may spurt out of the tube.

F2aTechnician

activity notesReaction of magnesium andhydrochloric acid

Practical Pupils observe magnesium reacting with hydrochloric acid and learn how to test for Core (Extension)hydrogen.


Sheet 1 of 1

F2a


ActivityCore

Most metals react with acids to give hydrogen. Your teacher will show you the reaction of magnesium with hydrochloric acid, and how to test for hydrogen. You will then carry out the reaction and test yourself.

Obtaining evidence1 Watch the demonstration by your teacher.2 Copy the table below. You just need one row.3 Set up a test tube as shown in the diagram.4 Put about 2 cm depth of dilute hydrochloric acid in the test tube.5 Add a small piece of magnesium ribbon and put a bung in the

tube to trap the hydrogen gas.6 Light a splint, remove the bung and test the gas in the tube

with the lighted splint.

Presenting the results7 Record your results in your table.

Considering the evidenceHow did you know that the acid reacted with the magnesium to make a new substance?Describe hydrogen.

Why did you need to use the bung to trap the hydrogen?Copy and complete this word equation for making hydrogen:

...................................... � hydrochloric acid → magnesium chloride � ......................................

Copy and complete this word equation for the reaction when hydrogen pops:

...................................... � oxygen → water

Reaction of magnesium andhydrochloric acid

bung to traphydrogengas

magnesiumand dilutehydrochloricacid

Name of gas How to test? Result if gas present

!

Wear eyeprotection.

Take care withacids. The

reaction may produceheat. Hot liquid mayspurt out of the tube.

�Extension

2

1

3

4

5


Running the activityPupils write a plan and make a prediction. Check pupils’ plans before they carryout the practical work. It should include:● five test tubes with bungs ready● acid of same depth in each test tube, not more than 1–2 cm● knowledge of which metal is which● metals ready to drop in● splints ready for the pop test● a prediction written● a results table ready● a clear explanation of what pupils intend to do.

Pipettes should be used to measure out hydrochloric acid, or pupils could make amark at the same height on each test tube and fill to that height.

Pupils may need help in understanding why it is a good idea to repeatexperiments. They look for patterns in their results, compare their results withtheir prediction and make a conclusion and evaluation.

Core: Pupils write up their own investigation and draw their own table based onthe format provided on the sheet.

Help: A much more structured framework is provided – pupils fill in answers onthe sheet to make their prediction, record their results, consider their evidenceand evaluate their experiment.

Other relevant materialIf pupils have not carried out Activity F2a they may need this activity sheet whichshows the test for hydrogen.

Expected outcomesPupils should conclude that most metals (Mg, Zn, Fe) react with hydrochloric acidto produce hydrogen. Some metals (Mg) react more vigorously than others. A fewmetals (Cu) do not react with hydrochloric acid at all. (NB: Pb and Ni react veryslowly.)

Safety notesPupils should wear eye protection. They should take care with acid. Considerableheat is generated with magnesium.

AnswersCore:

Check pupils’ results.

Help: Missing words are as follows:

fizzing or bubbles, hydrogen, a squeaky pop

Exceptions depend on the metals.

F2bTeacher

activity notesReacting metals with acids

Practical Pupils carry out a short investigation into the reaction of different metals with Core, Helphydrochloric acid.


1 2

12


Other relevant materialIf pupils have not carried out Activity F2a they may need this activity sheet whichshows the test for hydrogen.

EquipmentFor each group:● several metals, e.g. magnesium, zinc, copper, nickel, lead● five test tubes with bungs in a rack● splints

TipsIdeally the metals should all be in the same form, e.g. ribbon shapes cut from sheets tobe consistent with the magnesium. The sheets should be briefly sanded with emerypaper before being cut up to ensure that the surface metal is exposed.

Pupils will need access to a Bunsen burner, lit with the air hole closed, well away fromtheir experiments. Pipettes should be used to measure out hydrochloric acid, or pupilscould make a mark at the same height on each test tube and fill to that height.

For your information Running the activityPupils write a plan and make a prediction. Check pupils’ plans before they carry outthe practical work. It should include:● five test tubes with bungs ready● acid of same depth in each test tube, not more than 1–2 cm● knowledge of which metal is which● metals ready to drop in● splints ready for the pop test● a prediction written● a results table ready● a clear explanation of what pupils intend to do.

Pipettes should be used to measure out hydrochloric acid, or pupils could make a markat the same height on each test tube and fill to that height.

Pupils may need help in understanding why it is a good idea to repeat experiments.They look for patterns in their results, compare their results with their prediction andmake a conclusion and evaluation.

Core: Pupils write up their own investigation and draw their own table based on theformat provided on the sheet.

Help: A much more structured framework is provided – pupils fill in answers on thesheet to make their prediction, record their results, consider their evidence andevaluate their experiment.

Expected outcomesPupils should conclude that most metals (Mg, Zn, Fe) react with hydrochloric acid toproduce hydrogen. Mg reacts more vigorously than others. Cu does not react withhydrochloric acid at all. (NB: Pb and Ni react very slowly.)

Safety notesPupils should wear eye protection. They should take care with acid. Considerable heatis generated with magnesium.

F2bTechnician

activity notesReacting metals with acids

Practical Pupils carry out a short investigation into the reaction of different metals with Core, Help hydrochloric acid.


Sheet 1 of 1

F2b


ActivityCore

You are going to carry out a short investigation. You are going to mix different metals with hydrochloric acid and test for hydrogen.

Planning and predictingThe variable you are going to change is the type of metal. First writeyour plan:1 Find out what metals are available. Write the names down. These

are your values.2 You are going to try to keep all the other variables constant to make

it a fair test. Write down the other variables and explain how youwill keep each one constant.

3 Put 2 cm depth of hydrochloric acid into test tubes – one test tubefor each metal. Do not add your metals. Place your pieces of metalclose to the test tubes. Ask your teacher to check that your plan issafe and will work.

4 Write a prediction. Your prediction should answer these questions:● What will happen when you put the metal in the acid?● Will the type of metal make a difference?

5 Make a table like the one below for your results.

Obtaining evidence6 Carry out your plan once your teacher has checked it. Record your

results in your table.7 You may decide to repeat some of the tests. Show both results in

your table and remember to write down why you repeated that test.

Considering the evidence8 Write down what you found out.

EvaluatingCompare your results with your prediction. Were there anyanomalous results? (Anomalous results are results that you did notexpect.)Think carefully about your investigation. Write down three or moreimprovements that you would make if you started again.

Reacting metals with acids

Metal Description of What happened when you Did it give a positivemetal added the metal to acid? pop test?

2

1

Wear eyeprotection.

Take carewith acids.!

Sheet 1 of 2

F2b


ActivityHelp

You are going to carry out a short investigation. You are going to mix different metals with hydrochloric acid and test forhydrogen.

Planning and predicting

The variable you are going to change is the type of metal. First writeyour plan:

1 Find out what metals are available. List them below. These areyour values.

Metals: ...........................................................................................................................................

2 You are going to try to keep all the other variables the same tomake it a fair test. Complete the table below. (Hint: you couldkeep the acid that you react the metal with the same, and thetemperature.)

3 Put 2 cm depth of hydrochloric acid into each test tube. Do not add your metals. Place your pieces of metal close to the test tubes. Ask your teacher to check that your plan is safe andwill work.

4 Make a prediction by answering the questions below.What will happen when you put the metals in the acid?

..............................................................................................................................................................

Will it make a difference using different metals? ..........................................

Reacting metals with acids

Variable How I will keep it constant

Wear eyeprotection.


Sheet 2 of 2

F2b


ActivityHelp

Obtaining evidence5 Carry out your experiment once your teacher tells you to. Record your results below.

6 Look at your results. Do any of them look out of place? Do you think you shouldrepeat any tests? If so, add the results to the table.

7 Complete the sentences below:

I repeated tests on ................................................................................................................................................................

I repeated the tests because .........................................................................................................................................

Considering evidence8 Look at your results table and complete these sentences.

In general when I added a metal to an acid I observed ..........................................................................

I knew .............................................. gas was given off because there was a ................................................

with a lighted splint.

In my investigation the metals that gave unexpected results were ...............................................

..............................................................................................................................................................................................................

When I put this/these metal(s) with the acid, .........................................................

Evaluating9 Complete this table to compare your results with your prediction.

Reacting metals with acids (continued)

Questions My prediction My results Any unexpected results(from 4 above)

What will happenwhen you put themetals in the acid?

Will it make adifference usingdifferent metals?

Metal Description of What happened when you Did it give a positivemetal added the metal to acid? pop test?

2

1


Running the activityFirst demonstrate the reaction and show pupils how to test for carbon dioxide. Pupils then carry out the reaction themselves and practise the test for carbon dioxide.

Core: Pupils copy and complete a results table for the test for carbon dioxide, and answer questions about the reactions.

Extension: There are additional questions at the foot of the Core sheet asking pupils to write word equations, which can be cut off if not required.

Other relevant materialSkill sheet 15: Word equations

Expected outcomesPupils observe the fizzing when calcium carbonate is mixed with hydrochloric acid. When the gas is bubbled through limewater the limewater turns milky.

PitfallsThe mixture may froth out of the test tube before the delivery tube is fitted.If carbon dioxide is passed through limewater for long enough the limewater turns milky at first but then becomes clear again.

Safety notesEye protection must be worn. Pupils should take care with acid.

AnswersCore:

A gas was given off, indicated by the fizzing.

Carbon dioxide is a colourless gas that turns limewater milky.

Extension:calcium carbonate � hydrochloric acid → calcium chloride � water + carbon dioxide

The limewater changes from clear to milky.

a carbon dioxide � calcium hydroxide → calcium carbonate � waterb calcium carbonate

F3aTeacher

activity notesReaction of calcium carbonatewith hydrochloric acid

Practical Pupils observe the reaction of calcium carbonate with dilute hydrochloric acid and Core (Extension)learn how to test for carbon dioxide.


3

1

2

4

5


Other relevant materialSkill sheet 15: Word equations

Equipment For each group:● two test tubes in a rack● a bung fitted with a delivery tube ● calcium carbonate powder (one spatula measure)● a few cm3 of dilute hydrochloric acid● a few cm3 of limewater● a spatula

For your information Running the activityFirst demonstrate the reaction and show pupils how to test for carbon dioxide. Pupils then carry out the reaction themselves and practise the test for carbon dioxide.

Core: Pupils copy and complete a results table for the test for carbon dioxide, and answer questions about the reactions.

Extension: There are additional questions at the foot of the Core sheet asking pupils to write word equations, which can be cut off if not required.

Expected outcomesPupils observe the fizzing when calcium carbonate is mixed with hydrochloricacid. When the gas is bubbled through limewater the limewater turns milky.

PitfallsThe mixture may froth out of the test tube before the delivery tube is fitted.

If carbon dioxide is passed through limewater for long enough the limewaterturns milky at first but then becomes clear again.

Safety notesEye protection must be worn. Pupils should take care with acid.

F3aTechnician

activity notesReaction of calcium carbonatewith hydrochloric acid

Practical Pupils observe the reaction of calcium carbonate with dilute hydrochloric acid and Core (Extension)learn how to test for carbon dioxide.


glass tube

hydrochloricacid

limewater (calciumhydroxide solution)

calciumcarbonate

Extension

Sheet 1 of 1

F3a


ActivityCore

When acids react with carbonates the gas carbon dioxide is given off. Your teacher will show you the reaction of calcium carbonate with hydrochloric acid, and how to test for carbon dioxide. You will then carry out the reaction yourself and learn how to test for carbon dioxide.

Obtaining evidence1 Watch the demonstration by your teacher.2 Copy the table below. You just need one row.3 Set up the apparatus as shown in the diagram.4 Start the reaction by adding calcium carbonate

to the hydrochloric acid in a test tube and quickly replace the bung. The gas given off will bubble through the limewater.

Presenting the results5 Record your results in your table.

Considering the evidenceHow did you know that the acid reacted with calcium carbonate to make a new substance? Describe carbon dioxide.

Copy and complete this word equation for making hydrogen:

.......................... .......................... + hydrochloric acid →calcium chloride

+ water + .......................... ..........................

There is also a chemical reaction when carbon dioxide mixes with limewater (calcium hydroxide). How can you tell that there is a chemical reaction?a Copy and complete this word equation for the chemical reaction between

carbon dioxide and limewater (calcium hydroxide).

.......................... .......................... + calcium hydroxide → calcium carbonate + waterb What substance makes the limewater look cloudy? (Hint: look at the

products of the reaction.)

Reaction of calcium carbonatewith hydrochloric acid

glass tube

hydrochloricacid

limewater (calciumhydroxide solution)

calciumcarbonate

Name of gas How to test? Result if gas present

3

4

5

2

1

Wear eyeprotection.


�


Running the activityThis pen and paper activity could be set for homework or for a cover lesson.

Extension: there are optional prompts at the foot of the Core sheet, which can becut off and removed if required to form the Extension sheet without the prompts.

AnswersCore/Extension:

Hydrogen pops with a lighted splint. (Give credit for other correct statements.)

Carbon dioxide turns limewater milky. (Give credit for other correctstatements.)

People think that hydrogen and carbon dioxide are the same because they areboth colourless gases. However, they are different in many ways.

Carbon dioxide puts out fires while hydrogen burns. We know this becausecarbon dioxide is used in fire extinguishers while hydrogen explodes with apop when lit (as in the test for hydrogen).

Hydrogen is lighter than air but carbon dioxide sinks. The evidence for this isthat a balloon containing hydrogen floats while a balloon containing carbondioxide sinks.

Carbon dioxide can be made by reacting a carbonate with an acid whilehydrogen can be made by reacting a metal with an acid.

F3bTeacher

activity notesTwo colourless gases

Paper Pupils compare carbon dioxide and hydrogen. Core (Extension)


3

1

2

Sheet 1 of 1

F3b


ActivityCoreTwo colourless gases

carbondioxide

carbondioxide

hydrogen

hydrogen

Carbon dioxide and hydrogen look the same, but react very differently. You are going to read about carbon dioxide and hydrogen and then write a comparison.

1 Read the information and study the diagrams. ● Both carbon dioxide and hydrogen

are colourless gases.● Carbon dioxide

is heavier than air. Hydrogen is lighter than air.

● Hydrogen is so lightweight that it floats away from the Earth and into outer space. Carbon dioxide stays in the air.

● Hydrogen burns. Carbon dioxide is used to put out fires.

Write down anything else you know about hydrogen. Use bullet points.Write down anything else you know about carbon dioxide. Use bullet points.Write a comparison of hydrogen and carbon dioxide.

Copy and complete these sentences. Link your sentences together to make a paragraph.● People think that hydrogen and carbon dioxide are the same because ….

However, they are different in many ways.

● Carbon dioxide … while hydrogen …We know this because …

● Hydrogen… but carbon dioxide s......................................

The evidence for this is that a balloon containing …

● Carbon dioxide can be made by …while hydrogen can be made by …

�

2

3

1


Running the activityDemonstrate a hydrogen balloon exploding (if this was not done as a starteractivity for lesson F2): Fill a balloon with hydrogen from a cylinder. Tether theballoon to a clamp and stand surrounded by safety screens. Introduce a lightedtaper taped to the end of a metal rod between two of the screens to light thehydrogen gas in the balloon.

Also demonstrate the burning of magnesium and lighting a cigarette lighter.

Pupils then carry out a pen and paper exercise in which they think back over theburning reactions they have seen, and consider the energy that is given out inburning and how burning reactions are started off.

Safety notesPupils should wear eye protection while they observe the hydrogen demonstration.They should not look directly at the burning magnesium but observe it throughblue glass or look away when they have seen how bright it is.

Answers oxygen

Hydrogen burning: a flame, heat, light and sound are observed.

Magnesium burning: a flame, bright light and possibly some sound areobserved.

Lighter fuel burning: a flame, heat and light are observed.

Hydrogen burning: a small flame. Magnesium burning: a flame. Lighter fuelburning: a spark.

F4aTeacher

activity notesBurning and energy

Practical (demonstration), To introduce the concept of energy by looking at burning reactions. Corepaper


2

3

1


EquipmentFor the class (optional hydrogen demonstration):● a balloon● a hydrogen cylinder● a clamp and stand● string or thread● three safety screens● a taper● a metal rod, e.g. from a retort stand● a means of lighting the taper

For the class (optional magnesium demonstration):● a Bunsen burner● a heatproof mat● tongs● blue glass (for each pupil)● magnesium ribbon


Running the activityDemonstrate a hydrogen balloon exploding (if this was not done as a starteractivity for lesson F2): Fill a balloon with hydrogen from a cylinder. Tether theballoon to a clamp and stand surrounded by safety screens. Introduce a lightedtaper taped to the end of a metal rod between two of the screens to light thehydrogen gas in the balloon.

Also demonstrate the burning of magnesium and lighting a cigarette lighter.

Pupils then carry out a pen and paper exercise in which they think back over theburning reactions they have seen, and consider the energy that is given out inburning and how burning reactions are started off.

Safety notesPupils should wear eye protection while they observe the hydrogen demonstration.They should not look directly at the burning magnesium but observe it throughblue glass or look away when they have seen how bright it is.

F4aTechnician

activity notesBurning and energy

Practical (demonstration), To introduce the concept of energy by looking at burning reactions. Corepaper


Sheet 1 of 1

F4a


ActivityCore

You are going to use your knowledge of burning reactions tothink about energy.

The balloon explodes. There is a flash of light, a flame and a loudnoise. We need a small flame to get the chemical reaction going.

The magnesium burns. There is a bright white light. We need to heat the magnesium in a Bunsen burner flame to get the chemical reaction going.

1 Look at the pictures and read the descriptions above. Thinkabout other burning reactions you have seen.

In the reactions above, what gas are the hydrogen, magnesiumand lighter fuel reacting with?

Make a list of what happens when substances burn.

Sound, light and heat are energy. You have probably heard theword energy before. You may have been told you have too muchenergy, or too little energy. You may have eaten ‘high-energy’ foods.Energy is a very important scientific idea. You will learn a lot aboutenergy in science.

Burning reactions give out energy. You see the energy as light, youfeel it as heat and you hear it as sound.

Add to your lists the thing that is needed to get each burningreaction going.

Burning reactions do not start on their own. You need to put a smallamount of energy in to get them going. You need to strike a matchor use a spark to light the gas. Forest fires are often started by adiscarded match or cigarette. You need to put a small amount ofenergy in, but you get a large amount of energy out.

Burning and energy

2

3

1

The lighter fuel burns. There isa flame. The lighter makes aspark to get the chemicalreaction going.


Running the activityPupils work in groups to set up mini-fires and use sand, water and foam to putthem out. They time how long each fire takes to go out.Core: The method is given for the experiment, and there are structured questionsfor analysis and evaluation.Help: This gives a framework for recording, analysing and evaluating. It can beused in addition to the Core sheet for pupils who need it, or the activity can bedemonstrated.

Expected outcomesPupils should compare how quickly each method puts the fire out, and alsocompare their ease of use. They should realise how each method breaks the firetriangle.

PitfallsThe activity can be messy. Pupils should dry the bench and use a fresh heatproofmat or tin lid, if sufficient are available, for each of the three fires. A collection ofclean, used small food cans (e.g. cat food tins) are ideal for setting the fires in.Pupils should only be allowed to do this practical themselves if the teacher isconfident that they will remain under control. Pupils have a tendency to light thelargest fires they can and to misdirect their fire extinguishers. A teacherdemonstration may be safer.

Safety notesPupils should wear eye protection. Ensure pupils keep their fires small and remindthem about the risks of using acids. The foam may be acid and its use should becarefully controlled.

Answers Core:

sand or water

Check pupils’ results.

water or foam

water

They each remove part of the fire triangle: sand prevents oxygen reaching thefuel, water removes heat (energy), foam prevents oxygen reaching the fuel.


a sand or waterb Check pupils’ results.c sandd water

a oxygen or fuelb heat or energyc oxygen or fuel

F4bTeacher

activity notesPutting fires out

Practical Pupils compare and evaluate how quickly sand, water and foam put out a fire. Core, Help


3

1

2

4

5

1

2


Equipment For each group:● approximately 20 wooden splints (these could be provided ready broken in half

for the pupils)● three pieces of newspaper, approximately A4 size● three heatproof mats and/or tin lids● a stopclock● a 250 cm3 beaker containing approximately 100 cm3 of sand● a wash bottle of water● a measuring cylinder (to measure 50 cm3)● a delivery tube with jet inserted in rubber bung to fit the flask, as shown in the

diagram● a spatula● sodium hydrogencarbonate● dilute hydrochloric acid● an ignition tube● washing-up liquid

TipsIt is useful to collect tin lids or clean, small food cans (e.g. cat food tins) to lightthe fires in.

F4bTechnician

activity notesPutting fires out

Practical Pupils compare and evaluate how quickly sand, water and foam put out a fire. Core, Help


sand

00.0000.00

water 00.0000.00

acid

3 Fit the rubber bung and jet.

1 In a conical flask put: • 50 cm3 of water • 5 spatulas of sodium hydrogencarbonate • and a few drops of washing-up liquid. Swirl the flask.

2 Stand a small tube full of acid in the flask.

34

00.00

00.00


For your informationRunning the activityPupils work in groups to set up mini-fires and use sand, water and foam to putthem out. They time how long each fire takes to go out.

Core: The method is given for the experiment, and there are structured questionsfor analysis and evaluation.

Help: This gives a framework for recording, analysing and evaluating. It can beused in addition to the Core sheet for pupils who need it, or the activity can bedemonstrated.

Expected outcomesPupils should compare how quickly each method puts the fire out, and alsocompare their ease of use. They should realise how each method breaks the firetriangle.

PitfallsThe activity can be messy. Pupils should dry the bench and use a fresh heatproofmat or tin lid, if sufficient are available, for each of the three fires. A collection ofclean, used small food cans (e.g. cat food tins) are ideal for setting the fires in.Pupils should only be allowed to do this practical themselves if the teacher isconfident that they will remain under control. Pupils have a tendency to light thelargest fires they can and to misdirect their fire extinguishers. A teacherdemonstration may be safer.

Safety notesPupils should wear eye protection. Ensure pupils keep their fires small and remindthem about the risks of using acids. The foam may be acid and its use should becarefully controlled.

F4bTechnician

activity notesPutting fires out (continued)

Sheet 1 of 1

F4b


ActivityCore

You are going to find out what is the best material for putting out fires – sand, water or foam. Each time, record how long it takes for the fire to go out.

Obtaining evidence1 Make a table to record how long it takes for each fire to go out.

Your teacher may give you a sheet with a table to fill in.

Using sand

2 Take about six wooden splints and a piece of newspaper. Break the splints in half and crumple up the newspaper. Put them in the middle of a heatproof mat to make a fire.

3 Light your fire.4 Start the stopclock then carefully

pour a beaker of sand on to the fire.

Using water

5 Prepare another small fire and light it.6 Start the stopclock then squirt the water

on to the fire until it goes out.

Using foam

7 Take a conical flask and set it up as shown in the diagram.

8 Prepare a third small fire and light it.

9 Start the stopclock then turn the flask upside down, shake it and point the jet at the fire until it goes out.

Considering the evidence Which method was easiest to use?Which method put the fire out in the shortest time?Which method was the easiest to clean up after?Which method do you think would be most suitable for a large fire?Write down what each substance does when it puts out a fire:● sand ● water ● foam.

Putting fires out

sand

00.00

water 00.0000.00

acid

3 Fit the rubber bung and jet.

1 In a conical flask put: • 50 cm3 of water • 5 spatulas of sodium hydrogencarbonate • and a few drops of washing-up liquid. Swirl the flask.

2 Stand a small tube full of acid in the flask.

34

00.00

00.00

2

3

4

5

1

Wear eyeprotection.

Keep firesvery small.

Take care not to getacid or foam onanyone’s skin orclothes. Wash yourhands afterwards.

!

Sheet 1 of 1

F4b


ActivityHelp

Presenting the results1 Write your results in the table.

Considering the evidence Complete the sentences using these words:

a The easiest way to put out the fire was using ......................... .

b The fire was put out fastest by ......................... .

c The most mess to clear up was left by ......................... .

d The best method to use on a large fire would be ......................... .

When you put out a fire, you break the fire triangle.

a Using sand, which side of the fire triangle do you break?

......................................................................................................................................................

b Using water, which side of the fire triangle do you break?

......................................................................................................................................................

c Using foam, which side of the fire triangle do you break?

......................................................................................................................................................

Putting fires out

acid water foam sand

Method Time to put fire out in seconds

using sand

using water

using foam

2

1

Wear eyeprotection.

Keep firesvery small.

Take care not to getacid or foam onanyone’s skin orclothes. Wash yourhands afterwards.

!


Running the activityDemonstrate the burning candle. The pupils observe, discuss and explain what ishappening by answering the questions on the activity sheet.

Expected outcomesPupils should observe that the water level rises up as the candle burns andconclude that the burning candle is using up oxygen from the air.

PitfallsCare needs to be taken that a suitable sized container is used so that the rise inwater level is noticeable.

Safety notesCare needs to be taken with burning candles and hot wax.

Answers air

Because all the oxygen was used up.

There was oxygen in the air at the start.

It rose to take the place of the oxygen that was used up.

water and carbon dioxide

They stay in the large jar. Some of the water vapour condenses on the insideof the jar.

F4cTeacher

activity notesBurning candles

Practical (demonstration) Pupils watch a demonstration of a lighted candle floating on water inside a large glass Corecontainer. They observe the water rising up inside the container. This will help them plan their own investigation in Activity F4d.


3

1

2

4

5

6


Equipment For the class:● a bell jar● a trough of water● a candle on a small Petri dish such that the candle will float on the water inside

the bell jar


Running the activityDemonstrate the burning candle. The pupils observe, discuss and explain what ishappening by answering the questions on the activity sheet.

Expected outcomesPupils should observe that the water level rises up as the candle burns andconclude that the burning candle is using up oxygen from the air.

PitfallsCare needs to be taken that a suitable sized container is used so that the rise inwater level is noticeable.

Safety notesCare needs to be taken with burning candles and hot wax.

F4cTechnician

activity notesBurning candles

Practical (demonstration) Pupils watch a demonstration of a lighted candle floating on water inside a large glass Corecontainer. They observe the water rising up inside the container. This will help them plan their own investigation in Activity F4d.


air

floating candlebeaker

Petri dish

troughwater

Sheet 1 of 1

F4c


ActivityCore

You are going to watch a lighted candle floating on water insidea large glass container. You are going to explain what happens.

Obtaining evidence1 Your teacher will show you the experiment.

Considering the evidence2 In your group discuss the answers to the following questions.

What was in the large container?Why did the candle go out?Why didn’t it go out immediately?Why did the water rise up the container?What are the products when a wax candle burns?What happens to the products?

Burning candles

2

3

4

5

6

1

air


Petri dish

troughwater


Running the activityThe investigation is in three parts with three separate pupil sheets at Core andHelp level: planning the investigation (F4d), obtaining evidence (F4e) andconsidering and evaluating evidence (F4f). The demonstration in Activity F4cprepares pupils for this investigation.

Core, Help: In Activity F4d pupils plan their investigation. They may need quite abit of help to work out the method. A range of apparatus could be displayed tosuggest what they could use. They are encouraged to think about how they willmeasure the volume of air before and after burning. They also make a predictionabout what will happen to the volume of air as the candle burns. The Core sheetasks pupils to prepare a results table; Help sheet F4e provides a table for recording.

Check the plan, prediction and results table before pupils work in small groups tocarry out their plan in Activity F4e. Once pupils have collected their results theyshould be encouraged to look at them to see if any do not fit the pattern. If so,they should be repeated. They draw a graph of their results; the Help sheetprovides axes on which pupils draw their graph.

In Activity F4f pupils discuss in groups and answer questions to look at the resultsfrom their investigation and the graph they drew. They decide whether theprediction they made in Activity F4d was correct. The Help sheet provides extrasupport in the form of a structured format for pupils to record on the sheet.

Other relevant materialActivity sheet F4c

Expected outcomesPupils should produce a workable plan and make a prediction. They should inferthat the same proportion of the air (about 21%) is used up every time a candle isburned inside a container. The graph that they plot should be a straight line,showing that the amount of air left is directly proportional to the volume thatthey started with.

PitfallsThe dish containing the candle must be small enough to fit inside the containersthat are available. Care must be taken when putting the container over theburning candle that it doesn’t put the flame out.

It may be difficult to observe a rise in water level and it may be difficult using thisapparatus to get an accurate measure of the change in volume. The air inside thejar may expand with the heat of the burning candle. Carbon dioxide is soluble toa certain extent.

The carbon dioxide given out may put out the candle flame.

Safety notesCare must be taken with the hot wax that the pupils do not burn themselves orknock the candles over. Provide candles that are short and difficult to knock over.Pupils should ensure that candles are set in a firm base.

F4def

Teacheractivity notesInvestigate: How much air does a

candle need?

Paper, practical Pupils plan and carry out an investigation into the effect of burning candles in Core, Helpdifferent volumes of air. They measure the amount of air left after the candle has stopped burning.

They analyse their results and evaluate their experiment.



AnswersActivity F4d Core, Help:

Pupils may need help writing their plans depending on their ability. Below aresome suggestions.

Use different sized containers to put the candle in.

Fill the container with water. Then pour the water into a measuring cylinderand measure its volume.

The water level will rise up inside the container.

Mark the water level in marker pen on the side of the container.

Fill the container with water up to the mark, then pour the water into ameasuring cylinder and note the volume.

Five is a good number.

It is always a good idea to repeat practical measurements in case anythingunusual happens. Pupils should repeat any results that do not fit the patternonce they have their results.

Care must be taken with burning candles and hot wax that pupils do notburn themselves or knock the candles over. They should use candles that areshort and difficult to knock over and ensure that they are set in a firm base.

Core: possible table:

Help: Check pupils’ equipment lists.

down

Yes, the more air that you start with the more air will be left. (The amount ofair left is in proportion to the amount of air started with.)

Prediction: I think the amount of air that will be used up each time will varywith the amount of air we started with. This is because there is always thesame proportion of oxygen in the air, and this is the gas that is used up inburning.

Activity F4f Core, Help:

Pupils changed the amount of oxygen available to a burning candle. As aresult, the amount of air left at the end changed. The more air was available,the more air was left at the end.

The candle needs oxygen to burn. The candle burned for longer in the largercontainer because the volume of oxygen is greater in the larger container.

Check pupils’ predictions.

Answer depends on pupils’ results and whether they made any mistakes.

The candle may go out before all the oxygen is used up. A very low level ofoxygen may not sustain burning. The carbon dioxide given out by the candlemay put the candle out.

Pupils may suggest waiting for the air inside the container to cool down afterthe candle has burned before measuring the volume. Other improvementsdepend on individual experiments and the problems they encountered.

F4def

Teacheractivity notes

Volume of air Volume of air Volume of airat start in cm3 at end in cm3 used up in cm3

container 1

container 2

container 3

container 4

container 5

3

8

9

1

2

45

6

7

10

11

3

1

2

4

5

6

Investigate: How much air does a candleneed? (continued)


EquipmentFor each group (Equipment should be set out so that pupils can choose what theyneed for themselves, the exact requirements depending on pupils’ plans.):● a large trough or washing-up bowl● five containers of various sizes, e.g. beakers, jam jars, coffee jars● candles on small Petri dishes or floating candles (tea lights float quite well on

their own)● measuring cylinders (various sizes)● a marker pen (suitable for marking glass)

Other relevant materialActivity sheet F4c

For your informationRunning the activityThe investigation is in three parts with three separate pupil sheets at Core andHelp level: planning the investigation (F4d), obtaining evidence (F4e) andconsidering and evaluating evidence (F4f). The demonstration in Activity F4cprepares pupils for this investigation.

Core, Help: In Activity F4d pupils plan their investigation. They may need quite abit of help to work out the method. A range of apparatus could be displayed tosuggest what they could use. They are encouraged to think about how they willmeasure the volume of air before and after burning. They also make a predictionabout what will happen to the volume of air as the candle burns. The Core sheetasks pupils to prepare a results table; Help sheet F4e provides a table for recording.

Check the plan, prediction and results table before pupils work in small groups tocarry out their plan in Activity F4e. Once pupils have collected their results theyshould be encouraged to look at them to see if any do not fit the pattern. If so,they should be repeated. They draw a graph of their results; the Help sheetprovides axes on which pupils draw their graph.

In Activity F4f pupils discuss in groups and answer questions to look at the resultsfrom their investigation and the graph they drew. They decide whether theprediction they made in Activity F4d was correct. The Help sheet provides extrasupport in the form of a structured format for pupils to record on the sheet.

Expected outcomesPupils should produce a workable plan and make a prediction. They should inferthat the same proportion of the air (about 21%) is used up every time a candle isburned inside a container. The graph that they plot should be a straight line,showing that the amount of air left is directly proportional to the volume thatthey started with.

F4def

Technicianactivity notesInvestigate: How much air does a

candle need?

Paper, practical Pupils plan and carry out an investigation into the effect of burning candles in Core, Helpdifferent volumes of air. They measure the amount of air left after the candle has stopped burning.They analyse their results and evaluate their experiment.


air


Petri dish

troughwater


PitfallsThe dish containing the candle must be small enough to fit inside the containersthat are available. Care must be taken when putting the container over theburning candle that it doesn’t put the flame out.

It may be difficult to observe a rise in water level and it may be difficult using thisapparatus to get an accurate measure of the change in volume. The air inside thejar may expand with the heat of the burning candle. Carbon dioxide is soluble toa certain extent.

The carbon dioxide given out may put out the candle flame.

Safety notesCare must be taken with the hot wax that the pupils do not burn themselves orknock the candles over. Provide candles that are short and difficult to knock over.Pupils should ensure that candles are set in a firm base.

Technicianactivity notesInvestigate: How much air does a candle

need? (continued)

F4def

Sheet 1 of 1

F4d


ActivityCoreInvestigate: How much air does a

candle need?

Hint:look at the

apparatus thatis available.

You are going to burn a candle in different volumes of air and measure the amount of air left after the candle has stopped burning. In this activity you are going to plan your investigation and make a prediction.

Equipment● large troughs● containers of various sizes, e.g. beakers, jam jars,

coffee jars● candles on small Petri dishes or floating candles● measuring cylinders● marker pen

Planning 1 In your group, discuss these questions.

How will you change the volume of air available for burning?How will you measure the different volumes of air in your containers?How will you know that the volume of air changes as the candle burns?How will you mark the change in volume on your container?How will you measure the air left after the candle goes out?How many different volumes will you use?● Too many and you will not have time. ● Too few and you will not be able to see a

pattern in your results.Will you repeat any measurements? What safety measures will you take?

2 Write down your plan. Include all the points that you have discussed above and decide what equipment you should use.

3 Prepare a table for your results.

How many columns will you need? What should the headings be?

4 Check your plan and your table with your teacher.

Predicting5 You need to make a prediction about what you think might happen. In your

group, discuss these questions.

Will the volume of gas in the container go up or down as the candle burns?

Will the volume of air you start with affect how much air you have left?

6 Write down your prediction. Copy and complete this sentence, crossing out the incorrect words and filling in the space:

I think the amount of air that will be used up each time will/will not vary with theamount of air we start with. This is because there is always the same/a differentproportion of oxygen in the air, and this is the ...................................... that is used up in burning.

airfloatingcandle beaker

Petri dish

troughwater

Hint:what could you fillyour container with

that you couldmeasure thevolume of?Hint:

how did youfind out the volume

of air in your containerat the start?

23

456

78

9

1

10

11

Sheet 1 of 1

F4d


ActivityHelp

You are going to burn a candle in different volumes of air and measure the amount of air left after the candle has stopped burning. In this activity you are going to plan your investigation and make a prediction.

Equipment● large troughs● containers of various sizes, e.g. beakers, jam

jars, coffee jars ● measuring cylinders● candles on small Petri dishes or floating candles ● marker pen

Planning 1 In your group, discuss these questions and fill in the answers.

Input variable: How will you change the volume of air for burning?

..............................................................................................................................................................

How will you measure the different volumes of air in your containers?

..............................................................................................................................................................

How will you know that the volume of air changes as the candle burns?

..............................................................................................................................................................

How will you mark the change in volume on your container?

..............................................................................................................................................................

Outcome variable: How will you measure the air left at the end?

..............................................................................................................................................................

How many different volumes will you use? ● Too many and you will not have time.● Too few and you will not be able to see a pattern in your results.

..............................................................................................................................................................

Reliable results: Will you repeat any measurements?

..............................................................................................................................................................

What safety measures will you take?

..............................................................................................................................................................

Equipment: Choose the equipment you are going to use. Write a list.

..............................................................................................................................................................

PredictingWill the volume of air in the container go up or down as the candle burns?

..............................................................................................................................................................

Will the volume that you start with affect how much air you have left?

..............................................................................................................................................................

Investigate: How much air doesa candle need?

Hint:look at theapparatusavailable.

Hint:what could you fillyour container with

that you couldmeasure thevolume of?

Hint:how did youfind out the

volume of air atthe start?

Hint:why it might bea good idea to

repeatmeasurements?

Hint:think of any

hazards from aburning candle.

airfloatingcandle beaker

Petri dish

troughwater

2

3

4

5

6

7

8

9

1

11

10

Sheet 1 of 1

F4e



ActivityCore

You are going to burn a candle in different volumes of air and measure the amount of air left after the candle has stopped burning. You are going to carry out the plan that you made in Activity F4d.

Obtaining evidence1 After checking your plan and your results table with your teacher, carry out your plan.2 Record your results in your results table.

Presenting the results3 In your group, discuss how you should present the results. Are there any calculations

you need to do before you draw your graph? (Hint: do you need to know how muchair has been used up each time? How could you work this out?)

4 Before you draw your graph, look at your results table. Think of the variable that youchanged each time. This is the input variable and it should go on the x-axis. Think ofthe variable that you measured or calculated each time. This is the outcome variableand it should go on the y-axis.


Take carewith burning

candles and hotwax.

!

You are going to burn a candle in different volumes of air and measure the amount of air left after the candle has stopped burning. You are going to carry out the plan that you made in Activity F4d.

Obtaining evidence1 After checking your plan and your results table with your teacher, carry out your plan.2 Record your results in your results table.

Presenting the results3 In your group, discuss how you should present the results. Are there any calculations

you need to do before you draw your graph? (Hint: do you need to know how muchair has been used up each time? How could you work this out?)

4 Before you draw your graph, look at your results table. Think of the variable that youchanged each time. This is the input variable and it should go on the x-axis. Think ofthe variable that you measured or calculated each time. This is the outcome variableand it should go on the y-axis.

Take carewith burning

candles and hotwax.

!

F4eActivity

CoreInvestigate: How much air doesa candle need?

�

Sheet 1 of 1

F4e


ActivityHelp

You are going to burn a candle in different volumes of air andmeasure the amount of air left after the candle has stoppedburning. You are going to carry out the plan that you made inActivity F4d. You will then plot your results on a graph.

Obtaining evidence1 After checking your plan with your teacher, carry out your plan.2 Write your results in this table.

Presenting the results3 In your group, discuss what you need to do to the results before

drawing your graph. Do you need to do any calculations? (Hint: do you need to know how much air has been used up each time? How could you work this out?)

4 Draw your graph on the axes here.● Look at your results table.

Think of the input variable that you changed each time. This should go on the x-axis.

● Think of the outcome variable that you measured or calculated each time. This should go on the y-axis.

● Write numbers on the axes.

Investigate: How much air does acandle need?

Take care – sharp blade! Cut on asuitable surface.

!Take care withburning candlesand hot wax.

Change (input) ............................................

Title ............................................

Mea

sure

(ou

tcom

e) ..

......

......

......

......

......

......

......

Volume of air at Volume of air at Volume of air usedstart in cm3 end in cm3 up in cm3

container 1

container 2

container 3

container 4

container 5

Sheet 1 of 1

F4f


ActivityCore

You are going to look at your results and the graph from yourinvestigation, to help you decide whether the prediction you madein Activity F4d was correct.

Considering the evidence and evaluating1 In your group discuss these questions and decide on your answers.

a What did you change?b What happened as a result? (Look at your graph.)Why did this happen? (Explain the pattern scientifically if you can.)Was your prediction correct?Look at your graph. Did you get any unexpected (anomalous)results? Can you explain them?If so, why do you think these happened?Think about your investigation. Are there any improvements youwould make if you were starting again?


23

4

56

1

F4fActivity

Core

�

You are going to look at your results and the graph from yourinvestigation, to help you decide whether the prediction you madein Activity F4d was correct.

Considering the evidence and evaluating1 In your group discuss these questions and decide on your answers.

a What did you change?b What happened as a result? (Look at your graph.)Why did this happen? (Explain the pattern scientifically if you can.)Was your prediction correct?Look at your graph. Did you get any unexpected (anomalous)results? Can you explain them?If so, why do you think these happened?Think about your investigation. Are there any improvements youwould make if you were starting again?


23

4

56

1


Sheet 1 of 1

F4f


ActivityHelp

You are going to look at your results and the graph from yourinvestigation, to help you decide whether the prediction youmade in Activity F4d was correct.

Considering the evidence and evaluating1 In your group, discuss these questions and complete the

sentences. (Use your graph to help you.)

When we changed ...............................................................................................................

what happened to ................................................................................................................

was ...................................................................................................................................................

Why did this happen? .......................................................................................................

..............................................................................................................................................................

Was your prediction correct? Circle the answer.

yes/no

Look at your graph. Did you get any unexpected results?

..............................................................................................................................................................

If so, why do you think these happened?

..............................................................................................................................................................

Think about your investigation. Are there any improvements youwould make if you were starting again?

..............................................................................................................................................................


2

3

4

5

6

1


Running the activityPupils work in small groups, or alternatively, you might choose to demonstratethis activity. The three metals are heated in a Bunsen burner flame and pupilsrecord their observations.

Core: Instructions are given for the experiment. Pupils draw up their own table torecord the observations, and questions prompt them to draw conclusions.

Extension: There are extra questions at the foot of the Core sheet, which can becut off if not required. They ask pupils to write word equations.

Help: Instructions are given for the experiment. A table is provided for recording,and structured questions lead to conclusions.

Other relevant materialSkill sheet 12: Lighting a Bunsen burnerSkill sheet 15: Word equations (for Extension)

Expected outcomesPupils see that when magnesium, iron and copper burn, they produce newsubstances (oxides) and release energy.

Safety notesPupils should wear eye protection. Only small pieces of metals should beprovided. Warn pupils to take care heating the metals. Copper compounds areharmful. Magnesium burns with a very bright flame and must not be looked atdirectly. Pupils should be warned to look away when the magnesium burns, orview burning magnesium through blue glass.

Answers Core:

magnesium oxide, iron oxide, copper oxide

Light and heat are given out.

Magnesium, because it gives out the most light energy.

magnesium + oxygen → magnesium oxide

iron + oxygen → iron oxide

copper + oxygen → copper oxide

Extension:a phosphorus + oxygen → phosphorus oxideb carbon + oxygen → carbon dioxidec sulphur + oxygen → sulphur dioxide

calcium + oxygen → calcium oxide


a magnesium oxideb white powder solidc copper oxided iron oxide

A great deal of energy was given out (heat, light). A new product was formedwhich was different in appearance from the reactants.

magnesium

F5aTeacher

activity notesMaking oxides

Practical Pupils burn magnesium, iron and copper and see that they produce new substances Core (Extension), Help(oxides) and release energy.


3

12

4

5

6

3

1

2


Other relevant materialSkill sheet 12: Lighting a Bunsen burnerSkill sheet 15: Word equations (for Extension)

EquipmentFor each group:● a Bunsen burner● a heatproof mat● tongs● blue glass (for each pupil)● magnesium ribbon (1–2 cm)● steel wool (a walnut-sized piece)● copper foil (1–2 cm2)

For your information Running the activityPupils work in small groups, or alternatively, you might choose to demonstratethis activity. The three metals are heated in a Bunsen burner flame and pupilsrecord their observations.

Core: Instructions are given for the experiment. Pupils draw up their own table torecord the observations, and questions prompt them to draw conclusions.

Extension: There are extra questions at the foot of the Core sheet, which can becut off if not required. They ask pupils to write word equations.

Help: Instructions are given for the experiment. A table is provided for recording,and structured questions lead to conclusions.

Expected outcomesPupils see that when magnesium, iron and copper burn, they produce newsubstances (oxides) and release energy.

Safety notesPupils should wear eye protection. Only small pieces of metals should beprovided. Warn pupils to take care heating the metals. Copper compounds areharmful. Magnesium burns with a very bright flame and must not be looked atdirectly. Pupils should be warned to look away when the magnesium burns, orview burning magnesium through blue glass.

F5aTechnician

activity notesMaking oxides

Practical Pupils burn magnesium, iron and copper and see that they produce new substances Core (Extension), Help(oxides) and release energy.


Sheet 1 of 1

F5a


ActivityCore

When metals burn in air, they react with oxygen to make oxides. You are going to see what happens when three metals are burned in air.

Obtaining evidence and presenting the results1 Make a table to record your observations as you burn each metal.

Magnesium2 Using tongs, hold a small strip of magnesium ribbon in a Bunsen

burner flame until it burns. Remember not to look directly at the flame.

Iron3 Repeat the experiment with a small piece of iron wool.

Copper4 Finally, do the experiment with a small square of copper foil.

Considering the evidence What substance is formed when each metal (magnesium, iron and copper) burns?What do you see when each metal burns?Which of the metals would be best for making a distress flare for use at sea? Explain your answer.Copy and complete these word equations.

magnesium � ......................... → magnesium oxide

iron � oxygen → .........................

......................... � ......................... → copper oxide

The table shows the reactants and products for three other burning reactions. Write a word equation for each reaction shown in the table.Calcium metal burns in air with a dark red flame. Write a word equation for this reaction.

Making oxides

2

3

4

5

6

1

Reactants Products

phosphorus, oxygen phosphorus oxide

carbon, oxygen carbon dioxide

sulphur, oxygen sulphur dioxide

Wear eyeprotection.

Take carewith Bunsenburners.

Copper compoundsare harmful. Do notlook directly atburning magnesium.It will hurt your eyes.Look at it throughblue glass or lookaway when you haveseen how bright it is.

Wash your handsafterwards.

!

�Extension

Sheet 1 of 1

F5a


ActivityHelpMaking oxides

Wear eyeprotection.

Take carewith Bunsenburners.

Copper compoundsare harmful. Do notlook directly atburning magnesium.It will hurt your eyes.Look at it throughblue glass or lookaway when you haveseen how bright it is.

Wash your handsafterwards.

!

When metals burn in air, they react with oxygen to make oxides.You are going to see what happens when three metals are burned in air.

Obtaining evidence 1 Using tongs, hold a small strip of

magnesium ribbon in a Bunsen burner flame until it burns.

2 Write your observations in the table below.3 Repeat the experiment with a small

piece of iron wool.4 Do the experiment again with a small square of copper foil.

Presenting the results

Considering the evidence Complete these sentences to describe what happened when each metal burned.

a Magnesium burns in oxygen to form m...................................... o...................................... .

b Magnesium oxide is a w...................................... p...................................... s...................................... .

c Copper burns in oxygen to form c...................................... o...................................... .

d Iron burns in oxygen to form i...................................... o...................................... .

I know that a chemical reaction takes place when magnesium, iron and copper burn

in oxygen because ..................................................................................................................................................................

Which metal burned the brightest? ..............................................................................................................................

Metal What does the metal Observations during Observations afterlook like before heating? heating heating

magnesium

iron

copper

1

2

3


Running the activityProvide each group with a set of cards made from the Resource sheet, either byphotocopying the sheet onto card or by asking pupils to cut out the boxes fromthe sheet and stick them on card. Pupils arrange the cards as explained on thepupil sheet, to check progress and reinforce what they have learned aboutburning, acids reacting with metals and acids reacting with carbonates. Pupilsthen make their own sets of cards to create some more examples of the threetypes of reaction.

Other relevant materialFor each group:Resource sheet F5b, copied onto card if possibleSkill sheet 15: Word equationsScissors

Answers

F5bTeacher

activity notesChemical reactions

Paper Pupils use words and phrases in a card game to help them make generalisations about Core, the three types of chemical reaction covered in this unit. Resource


Chemical Reactants Products Examplesreaction

burning oxygen and another oxides sulphur + oxygen → sulphur dioxidesubstance

acid neutralised an acid and a carbon dioxide (and nitric acid + magnesium carbonateby carbonate carbonate two other products) → magnesium nitrate + water

+ carbon dioxide

acid neutralised an acid and a metal hydrogen (and sulphuric acid + calcium by metal another product) → calcium sulphate + hydrogen

Sheet 1 of 1

F5b


ActivityCore

You are going to use cards to revise what you know about chemical reactions.1 Look at the cards from the Resource sheet. Pick out the cards that refer to

all chemical reactions. You can recognise them as the words are in bold.2 Arrange these cards in a row like this:

3 Sort the other cards so that they are all in the correct column.4 Rearrange the cards in the columns so that:

● one row across is about burning● one row across is about acids reacting with carbonates● one row across is about acids reacting with metals.

5 Ask your teacher to check your cards, or ask for help if you get stuck.6 Make your own cards to show two other examples for each type of reaction.

Add your cards to the ones on the table.7 If there is time, record your arrangement of cards as a table.

Chemical reactions

Chemical reaction Reactants Products Examples

You are going to use cards to revise what you know about chemical reactions.1 Look at the cards from the Resource sheet. Pick out the cards that refer to

all chemical reactions. You can recognise them as the words are in bold.2 Arrange these cards in a row like this:

3 Sort the other cards so that they are all in the correct column.4 Rearrange the cards in the columns so that:

● one row across is about burning● one row across is about acids reacting with carbonates● one row across is about acids reacting with metals.

5 Ask your teacher to check your cards, or ask for help if you get stuck.6 Make your own cards to show two other examples for each type of reaction.

Add your cards to the ones on the table.7 If there is time, record your arrangement of cards as a table.

Chemical reaction Reactants Products Examples


F5bActivity

CoreChemical reactions

✂

Sheet 1 of 1

F5b


ActivityResourceChemical reactions

Ch

emic

al r

eact

ion

Rea

ctan

tsPr

od

ucts

Exam

ple

s

burn

ing

acid

neu

tral

ised

by

carb

onat

eac

id n

eutr

alis

ed b

y m

etal

oxyg

en a

nd a

noth

ersu

bsta

nce

an a

cid

and

a ca

rbon

ate

an a

cid

and

a m

etal

oxid

esca

rbon

dio

xide

(an

d tw

oot

her

pro

duct

s)

hydr

ogen

(an

d an

othe

rp

rodu

ct)

sulp

hur�

oxyg

en→

sulp

hur

diox

ide

nitr

ic a

cid

�m

agne

sium

car

bona

te→

mag

nesi

um n

itrat

e�

wat

er�

carb

on d

ioxi

de

sulp

huric

aci

d�

calc

ium

→ca

lciu

m s

ulp

hate

�hy

drog

en

�

�


Running the activityThis demonstration is best done with a micro-burner instead of a full size Bunsenburner. If a micro-burner is not available then use a Bunsen burner with the flamemade very small by reducing the gas supply.

Dried cobalt chloride paper can be used to detect water: it needs to be stored in adesiccator before use. Limewater is used to detect carbon dioxide. The test forwater should be demonstrated before the experiment with a second piece ofcobalt chloride paper. Pupils need reminding of the test for carbon dioxide andthat methane is a fossil fuel.

The burner is lit and the water turned on to draw the waste gases past the cobaltchloride paper and through the limewater.

Other relevant materialSkill sheet 16: Energy transfer diagrams

Expected outcomesThe cobalt chloride paper turns from blue to pale pink. The limewater turns fromclear to cloudy.

Safety notesAll present should wear eye protection. The apparatus will get hot, even if a smallflame is used. Allow it to cool before disassembling.

Answersoxygen

carbon dioxide

carbon + oxygen → carbon dioxide

water

hydrogen + oxygen → hydrogen oxide (water)

a Most fuels contain hydrogen and carbon.

b Some fuels contain either carbon or hydrogen.

F6aTeacher

activity notesBurning fossil fuels

Practical (demonstration) Pupils watch a demonstration to show that carbon dioxide and water are produced when Corefossil fuels burn. They link their observations to their knowledge and understanding.


Fuel Result with Result with Does this fuel Does this fuelcobalt chloride limewater contain carbon? contain hydrogen?

ethane pink cloudy yes yes

coke blue cloudy yes no

petrol pink cloudy yes yes

hydrogen pink clear no yes

wood pink cloudy yes yes

candle wax pink cloudy yes yes

3

1

2

45

6

7


Other relevant materialSkill sheet 16: Energy transfer diagrams

Equipment For the class:● a micro-burner or Bunsen burner● a heatproof mat● two retort stands with clamps● glassware and connections as shown in the diagram● dry cobalt chloride paper● limewater● water suction pump

Set up the equipment as shown in the diagram, and connect it to a tap via a suction pump.

For your information Running the activityThis demonstration is best done with a micro-burner instead of a full size Bunsen burner. If a micro-burner is not available then use a Bunsen burner with the flame made very small by reducing the gas supply.

Dried cobalt chloride paper can be used to detect water: it needs to be stored in a desiccator before use. Limewater is used to detect carbon dioxide. The test for water should be demonstrated before the experiment with a second piece of cobalt chloride paper. Pupils need reminding of the test for carbon dioxide and that methane is a fossil fuel.

The burner is lit and the water turned on to draw the waste gases past the cobaltchloride paper and through the limewater.

Expected outcomesThe cobalt chloride paper turns from blue to pale pink. The limewater turns fromclear to cloudy.

Safety notesAll present should wear eye protection. The apparatus will get hot, even if a smallflame is used. Allow it to cool before disassembling.

F6aTechnician

activity notesBurning fossil fuels

Practical (demonstration) Pupils watch a demonstration to show that carbon dioxide and water are produced when Corefossil fuels burn. They link their observations to their knowledge and understanding.


cobalt chloridepaper

to suctionpump on tap

limewater

methane

mat

Sheet 1 of 1

F6a


ActivityCore

You are going to watch a demonstration to find out what is produced when methane burns.

Considering the evidenceWhat substance is needed for all burning reactions?What substance turns limewater milky?Copy and complete this word equation: ......................... � oxygen → carbon dioxide

1 Cobalt chloride is a test for water. Dry cobalt chloride is blue. Wet cobalt chloride is pale pink. Try this with blue cobalt chloride paper.

What other product is made when methane is burned?Water is also an oxide. The scientific name for water would be hydrogen oxide, but everyone calls it water.Copy and complete this word equation: ......................... � oxygen → hydrogen oxide (water)

Carbon makes carbon dioxide when it burns and hydrogen makes hydrogen oxide (water) when it burns. Methane must contain both carbon and hydrogen, because it makes carbon dioxide and water when it burns. Fuels that contain carbon and hydrogen are called hydrocarbons.

The table shows the results of similar experiments with other fuels. Copy it and use what you have learned to complete the last two columns.

Write a conclusion: copy and complete these two sentences.a Most fuels …b Some fuels …

Burning fossil fuels

cobalt chloridepaper

to suctionpump on tap

limewater

methane

mat

Wear eye protection for thisdemonstration.

Fuel Result with Result with Does this fuel Does this fuelcobalt chloride limewater contain carbon? contain hydrogen?

ethane pink cloudy

coke blue cloudy

petrol pink cloudy

hydrogen pink clear

wood pink cloudy

candle wax pink cloudy

2

3

4

5

6

7

1

F1


PlenariesChanging materials

Sheet 1 of 1

Review learning● Pupils working in pairs sort a series of cards into

examples of physical and chemical change. Carry outa class scan to check which examples are causingdifficulty. Pupils justify classification.

Sharing responses● Pupils discuss the reactions and identify the key

evidence observed to support or challenge the idea thata chemical reaction has taken place.

Group feedback● Pupils working in pairs look at unfamiliar examples of

chemical reactions and identify reactants and products.Pupils identify the clues they used in the information tomake their decisions.

Word game● Pupils match words with definitions. (For Red book

users.)

Looking ahead● The question can be set for individuals to consider and

suggest answers to. They then share responses withother pupils. Make it clear that they may not know theanswer and need to suggest their ideas.

● Suggestions can be summarised and recorded in thepupils’ books to then reconsider after further lessons.



Pupils classify a range ofexamples as representingphysical or chemicalchange.

In groups, pupils sharetheir observations fromActivity F1a.

Pupils identify reactantsand products indescriptions of reactions.

Pupils match words anddefinitions.

Pupils suggest whatevidence they would needto collect to see if acidsreact with metals.

➔ Pupil sheet

➔ Pupil sheet

➔ Pupil sheet

QuestionWhat evidence would you need to collectto see if acids react with metals?


Review learningSort these cards into two groups:

F1 PlenariesChanging materials

Physical changes Chemical changes�

adding vinegar to

bicarbonate of soda

cheese going

mouldy

milk turning souradding hot water

to pot noodles

bicycle tyre

going flatcandle burning

painting nails

with nail varnishbreaking an egg

steam condensing

on a windowchocolate melting

burning methaneadding magnesium

to acid

�


Group feedbackFor each reaction described below, write down the substances that thereaction starts with (reactants) and the new substance(s) produced in thereaction (product(s)). Use two columns in your book headed:

Starting substances New substance(s)

1 Sulphur is a yellow solid that burns in air with a blue flame to producesulphur dioxide gas, which is acidic and poisonous.

2 Hydrogen gas will burn in oxygen gas and produce a colourless liquid,which is water.

3 Methane gas burns in air to produce carbon dioxide gas and water.

4 Iron metal reacts with oxygen to form a reddish brown substance callediron oxide.

5 Vinegar (ethanoic acid) removes the limescale (calcium carbonate) fromkettles. The limescale fizzes when the vinegar makes contact with it.


F1 Plenaries

�


Group feedbackFor each reaction described below, write down the substances that thereaction starts with (reactants) and the new substance(s) produced in thereaction (product(s)). Use two columns in your book headed:

Starting substances New substance(s)

1 Sulphur is a yellow solid that burns in air with a blue flame to producesulphur dioxide gas, which is acidic and poisonous.

2 Hydrogen gas will burn in oxygen gas and produce a colourless liquid,which is water.

3 Methane gas burns in air to produce carbon dioxide gas and water.

4 Iron metal reacts with oxygen to form a reddish brown substance callediron oxide.

5 Vinegar (ethanoic acid) removes the limescale (calcium carbonate) fromkettles. The limescale fizzes when the vinegar makes contact with it.

Changing materials


Word gamePair up each word with its correct definition.


This produces a new substance. It is also called a reaction.

A summary in words to record whatchemical change has taken place.

Any substance that is taking part in achemical reaction. The substance is

chemically changed.

Any new substance produced by achemical reaction.

Symbol used in a word equation toseparate the reactants from the

products.

The appearance of something is changed without changing what

it is made of.

Word Definition

arrow

product

word equation

chemical change

physical change

reactant

F2


PlenariesAcids and metals

Sheet 1 of 1

Review learning● Explain what a generalisation is and give some

examples.

● Ask pupils to write a general rule to summarise thepattern they have observed.

Sharing responses● Pupils carry out reactions and share responses to

questions on the activity sheets.

● Encourage pupils to say what evidence they observed toidentify the reaction as a chemical reaction.

● Ask pupils to suggest why the pop can vary.

Group feedback● Pupils compare their data from the activity. They

identify similarities and differences.

● They discuss any differences and suggest what theycould do to establish if an error has taken place.

● They discuss whether the evidence collected supportstheir initial prediction and what their final conclusionis.

Word game● In pairs, pupils prepare four questions about the science

in today’s lesson starting one question with each of thewords: What, When, Why and How. Pupils must be ableto answer their question correctly.

● Pupils then swap questions with another pair andanswer them. If time is too short, the questions could beused at the start of the next lesson to recap.

Looking ahead● Explain that some foods contain acids and that bacteria

in the mouth form acid.

● The question can be set for individuals to consider andsuggest answers to. They then share responses withother pupils. Make it clear that they may not know theanswer and need to suggest their ideas and predictions.

● Suggestions can be summarised and recorded in pupils’books to reconsider after further lessons.



Pupils write a general ruleto summarise the patternthey have observed.


In groups, pupils discusstheir answers to ActivityF2b.

A quick quiz game. Pupils suggest why dentiststend to use gold or mercuryfor fillings.

QuestionWhy do dentists tend to use gold ormercury for fillings?

F3


PlenariesAcids and carbonates

Sheet 1 of 1

Review learning● Explain what a generalisation is and give some examples.

● Ask pupils to write a general rule to summarise the patternthey have observed.

Sharing responses● Pupils describe and compare their description of carbon

dioxide gas.

● Pupils suggest why they have to bubble the gas into thelimewater.

● Pupils compare their word equations for the reaction ofmetal and carbonate. What are the reactants? What are theproducts? Does it matter what is written first, second andlast?

Group feedback● Ask pupils to share information they listed about

hydrogen and/or carbon dioxide. Summarise points on theboard.

● Ask pupils to identify from their information, whichproperties are the same for each gas and which are different.

● Ask pupils to identify which information they would needto use to spot the hydrogen gas in a group of mystery gases.

Word game● Give each pupil a card containing a question and a

response. Ask a pupil to begin by standing up and readingout the question section only of their card and sittingdown. The pupil who has an appropriate response to thisquestion stands up, gives their response and then asks thequestion they have on their card and sits down and so on.

● The game is complete when the first pupil stands up for thesecond time to read out the response section of their card.

● If there are not enough cards for the whole class, pairs ofpupils can share a card.

Looking ahead● The question can be set for individuals to consider and

suggest answers to. They then share responses with otherpupils. Make it clear that they may not know the answerand need to suggest their ideas and predictions.




Pupils write a general ruleto summarise the patternthey have observed.

In groups, share responsesto Activity F3a.

Whole-class discussion ofanswers to Activity F3b.

Check progress by playingloop game with key wordsfrom unit so far.

Pupils suggest otherreactions in which carbondioxide gas is produced.

➔ Pupil sheet

QuestionIn what other reactions is carbon dioxidegas produced?


Word game

F3 PlenariesAcids and carbonates

�

�

QThe carbonate often called marblechips.

ALimewater

QName for a reactionin which somethingnew is formed.

ACalciumcarbonate

QThese suggest that agas is beingproduced in areaction.

AChemicalreaction

QNoise heard whenyou test positivelyfor hydrogen gas.

ABubbles

QColour change thatoccurs in limewaterwhen carbondioxide is present.

ASqueak

QGas released when acarbonate reactswith an acid.

ACloudy/milky

QSign detected by athermometer that achemical reactionhas taken place.

ACarbon dioxide

QEvidence of achemical reactiondetected byuniversal indicator.

ATemperaturechange

QEvidence of achemical reactionthat our eyes candetect.

ApH change

QName for startingmaterials in achemical reaction.

AColour change


F3 PlenariesAcids and carbonates (continued)

�

�

QName for newmaterials producedin a chemicalreaction.

AReactants

QA property of aphysical change.

AProducts

QAn example of thischange is icemelting.

AIt can easily bereversed

QShorthand way ofdescribing achemical reaction.

APhysical change

QMetal that is usedby dentists becauseit doesn’t react withacid.

AWord equation

QMetal that producesmagnesium chloridewith hydrochloricacid.

AGold

QA property of achemical change.

AMagnesiumribbon

QForm of carbonateused onblackboards.

AIt is not easilyreversible

QProduct formedwhen hydrogenburns in oxygen.

AChalk

QSolution used todetect carbondioxide gas.

AWater

Word game

F4


PlenariesFirefighting

Sheet 1 of 1

Review learning● Pupils brainstorm issues related to clear communication

for elderly residents, e.g. large font size, minimumnumber of words.

● Pupils discuss and identify specific fire risks that elderlypeople may be prone to.

● They draw their posters and then look at each other’sideas.

Sharing responses● Pupils compare their list of what happens when

substances burn.

● Pupils discuss what is needed to get a burning reactiongoing and what is produced.

Group feedback● Ask pupils to rank their data for how long each

firefighting method took to extinguish the fire and tocompare results. Discuss any patterns.

● Invite specific groups to describe how the water, foamor sand puts out the fire.

● Ask pupils to suggest in what circumstances it would beadvisable to use each of these methods.

Word game● Ask pupils to devise questions relating to the lesson.

They must know the answer to their questions.

● Play ‘Mastermind’ with one pupil taking the ‘hot seat’and the rest of the class asking questions. The pupilstays in the ‘hot seat’ until he or she gives an incorrectanswer.

Looking ahead● Explain that water is a product of burning.

● The questions can be set for individuals to consider andsuggest answers to. They then share responses withother pupils. Make it clear that they may not know theanswer and need to suggest their ideas and predictions.




Pupils create fire triangleposter with advice forelderly residents.


In groups, pupils discusstheir responses to ActivityF4b.

Play ‘Mastermind’. Pupils suggest what teststhey would carry out toidentify the presence ofwater.

QuestionsWhat tests would you carry out to identifythe presence of water?

How would you establish whether or notthe water was pure?

F4


PlenariesInvestigate: How much airdoes a burning candle need?

Sheet 1 of 1

Review learning● Pupils say what values they chose for the things they

were going to keep the same and for independentvariables.

● Discuss what other variables were identified in theinvestigation.

● Ask pupils to say how they laid out their results tables.

Group feedback● In groups, pupils discuss the predictions they made. Ask

them to justify why they made them.

● Ask them to discuss any differences in the predictions inthe group.

Analysing● Ask pupils to suggest what pattern they can see in the

data they have collected.

● Ask them to describe, in a sentence, what they think isthe relationship between burning and air.

● Discuss if the conclusion matches with theirpredictions.

Evaluating● Discuss whether all the groups doing each investigation

have the same results and if not why not.

● Ask a pupil from each investigation to describe howthey collected the data, i.e. what strategies they used.

● Ask pupils to suggest whether or not any variation inthe data from all the groups could be caused by theirmethod and procedures. Help them to identify whatparts of the method could have resulted in errors.

● Ask pupils to suggest what they might do differently toobtain better results.

Review learning Group feedback Analysing Evaluating


Teacher-led discussion of theplanning procedure.

Pupils share their predictions. Teacher-led discussion of the datacollected.

Teacher-led discussion on howreliable the data is and how itcould be improved.

F5


PlenariesBurning changes

Sheet 1 of 1

Review learning● Pupils work in pairs to write a golden rule for other

pupils that summarises the behaviour of magnesium,iron and copper when burnt in air.

● Ask pupils to share their ideas so that a golden rule isagreed by the class.

Sharing responses● Pupils discuss observations for magnesium, iron and

copper burning in air.

● They identify evidence to suggest that a chemicalchange takes place.

Group feedback● Pupils work in pairs to write word equations for

magnesium, iron and copper burning in air.

● Carry out a class scan and look for examples where wordequations begin with: oxygen � … or air � … andexplain that the use of oxygen is more accurate than airto represent the chemical reaction – link this back to thecandle activity.

● Again, with an example from the class scan, discusswhether it is important that the word equation beginswith the metal or with oxygen.

● Ask if a general word equation can be written tosummarise what happens when any metal burns inoxygen.

Word game● Pupils take the cards and match them together to make

word equations describing burning reactions.

Looking back● Pupils revise and consolidate knowledge from the unit.

They can use the Unit map, Pupil check list, or the Testyourself questions.

Review learning Sharing responses Group feedback Word game Looking back


Pupils summarise in asentence what happenswhen a substance burns.

Pupils discuss observationsfrom Activity F5a.

Pupils compare wordequations and discussconventions.

Match halves of wordequations about burningmetals and fuels.

Pupils revise andconsolidate knowledge fromthe unit.

➔ Pupil sheet

➔ Unit map

➔ Pupil check list

➔ Test yourself


Word gameMatch two cards together to build word equations about burning reactions.

Reactants Product(s)

F5 PlenariesBurning changes

copper � oxygen

sodium � oxygen

phosphorus � oxygen

magnesium � oxygen

zinc � oxygen

iron � oxygen

hydrogen � oxygen

carbon � oxygen

sulphur � oxygen

methane � oxygen

_ zinc oxide

_ carbon dioxide

_ copper oxide

_ sulphur dioxide

_ magnesium oxide

_ sodium oxide

_ iron oxide

_ phosphorus oxide

_ carbon dioxide + water

_ hydrogen oxide (water)

F6


PlenariesGetting hotter – Think about

Sheet 1 of 1

Group feedback● In groups, pupils explain why they think scientists need

to test their ideas and models.

● Give some further ideas on scientists testing their ideasand using models, e.g. the particle model and models ofelectricity.

Bridging to other topics● Tell pupils they will need the skill of finding

relationships between data in many other units,especially full investigations.

● Give some examples of patterns and relationships indata and ask pupils to suggest some more.

Group feedback Bridging to other topics

In groups, pupils discuss why they Ask pupils to think of instances where think scientists need to test their relationships between variables could be ideas and models. used in other contexts. Many investigations

will need pupils to be able to findrelationships in data.


ExamplesThere is a relationship between the lengthof a shadow and the time of day.

There is a relationship between temperatureand how quickly an ice cube melts.

There is a relationship between thetemperature of water and how much sugarwill dissolve.

F1


SpecialsChanging materials

1 Pick the correct words to finish the sentences.

a Burning wood is a physical / chemical change. It is reversible / irreversible. This means that once it changes, you can’t change it back!

b Melting ice is a physical / chemical change. It is reversible / irreversible. This means that if ice melts, you can freeze it to get ice again.

2 Look at these everyday changes. Which of them arechemical changes? Draw circles around them.

Sheet 1 of 2

Cross outthe wrong words.

Underline theright words.

egg frying fireworks

frostforming

puddles drying

candleburning

rusty car

F1


SpecialsChanging materials (continued)

3 Read these descriptions carefully.

Sheet 2 of 2

4 Use these words to fill in the gaps.

During a chemical reaction the ...................................... join

together. New ...................................... are made. These are

called ...................................... .

substances products reactants

There are bubbles.

The mixture gives out

heat energy.

The mixture stays thesame temperature.

The mixture does not stay

the same temperature.

The colour changes and stays changed.

Which are signs that a chemical change has happened?Colour them in red.

No substances are used up.

There is a flame.

The mixture gives

out coloured light.

The colour changes then changes back.

F2


SpecialsAcids and metals

1 Joe adds zinc to sulphuric acid. What does he see? Tick the box.

bubbles

a blue light

a black solid

2 Here are the instructions for testing a gas to see if it ishydrogen. They’re all mixed up!

a Write numbers in the boxes to put them in order.

b If the gas is hydrogen, the lighted (burning) splintwill …

… turn red

… give a squeaky pop

… go out.

Sheet 1 of 2

A squeaky popmeans it’shydrogen.

Let the gas mixwith air.

Test with a lightedsplint.

pop!

Tick thebox to show the

right answer.

F2


SpecialsAcids and metals (continued)


Some metals react with ............................................ and form

............................................ . Hydrogen ............................................ with a

burning splint.

4 Iron rusts. Draw a circle round the things in the listthat are needed for iron to rust.

Sheet 2 of 2

oil

water

hydrogen

oxygensugar

paint

popshydrogen acids

F3


SpecialsAcids and carbonates

1 Julie adds calcium carbonate to acid. What does she see? Tick the box.

a fossil a green solid bubbles

2 Here are the instructions for testing a gas to see if it is carbon dioxide. They’re all mixed up!

a Write numbers in the boxes to put them in order.

b If the gas is carbon dioxide, the limewater will ...

... turn pink ... turn milky ... turn yellow.

3 If you mix calcium carbonate and hydrochloric acid, carbon dioxide is formed.

Here are some sentences about this reaction. Match the beginnings and endings.

Sheet 1 of 2

If the limewatergoes milky, it’scarbon dioxide

Collect someclear, colourlesslimewater.

Bubble the gasthrough thelimewater.

The reaction is a …… carbon dioxide

The reactants are …

A product is…

… neutralisation

… carbonate and acid

Tick thebox.

F3


SpecialsAcids and carbonates (continued)

4 Jamal added hydrochloric acid to some coppercarbonate powder. A gas was made. He tested some ofthe gas with a lighted (burning) splint and some of thegas with limewater.

a Show what happens in these tests by finishing thediagrams.

b Fill in the gap.

When a metal carbonate reacts with an acid,

............................................................... gas is made.

5 a Pick out the carbonate rocks from this list. Colourthem in red.

b Cross out the wrong word. Underline the rightword.

Acids / Alkalis in the surroundings will slowly wearaway statues made of marble.

Sheet 2 of 2

hydrochloricacid

test the gasmade

burningsplint

limewatercoppercarbonate

granite

chalk

sandstonelimestone

marble

slate

F4


SpecialsFirefighting


Burning uses up part of the ............................................ . The part

it uses is the gas ............................................ .

The name for the burning reaction is ............................................ .

A material that burns is a ............................................ . When you

light a fuel, you give it ............................................ .

2 The fire triangle shows what’s needed for a fire.

a Fill in the sides of this fire triangle. Use words from question 1.

b To put out a fire, you take away one side of the fire triangle. Here are some ways of putting out fires.

Which side of the fire triangle has been taken away in each one?

i Putting a damp towel on a chip pan fire. The

towel takes away the ...................................... .

ii Covering a petrol fire with foam. The foam takes

away the ...................................... .

iii Putting water on a paper fire. The water cools it

and takes away some ...................................... .

iv Cutting down trees to stop a forest fire. Cutting

the trees down takes away the ...................................... .

Sheet 1 of 1

combustion oxygen airenergy

fuel

F5


SpecialsBurning changes

1 a Cut out the jigsaw pieces at the bottom of thepage. Then match them up to make a wordequation for carbon burning. When you’re sure,stick them down.

b Colour the reactants in red. Colour the product inblue.

2 Use these words to fill in the gaps. You may not needall the words.

a When metals burn in air, they react with

........................................... gas.

b Metals form new substances called metal

........................................... when they react with oxygen gas.

c Other materials can react with oxygen and they

make ........................................... as well.

Sheet 1 of 2

carbon dioxideoxygen

carbon �

hydrogencarbonatesoxides oxygen

✂

F5


SpecialsBurning changes (continued)

3 Which of these word equations are for burningreactions? Colour them in red.

Sheet 2 of 2

4 Use these words to finish off the word equations forburning reactions.

a zinc + oxygen → zinc ...........................................

b carbon + oxygen → ........................................... dioxide

c ........................................... + oxygen → sodium oxide

d wood + ........................................... → carbon dioxide + water

e ........................................... + oxygen → water

oxide carbon oxygen hydrogen sodium

iron + chlorine → iron chloride

magnesium + oxygen → magnesium oxide

aluminium + chlorine → aluminium chloride

petrol + oxygen → carbon dioxide + water

lead + oxygen → lead oxide

carbon + oxygen → carbon dioxide

F6


SpecialsGetting hotter

1 Match the words to their descriptions.

Sheet 1 of 2

The amount ofcarbon dioxide in

the air is increasing.

Carbon dioxidegas traps theEarth’s heat.

The Earth will gethotter if more heat

is trapped.Oxygen gas trapsthe Earth’s heat.

The amount of oxygen in the air is increasing.

The Earth will gethotter if less heat

is trapped.

fuels

oxygen

carbon dioxideand water

coal, petrol and wood

these are produced(made) when fuels burn

this gas is needed for things to burn

these are fuels

we burn these to get energy

2 The greenhouse effect may make the Earth too hot.

Colour in red the statements that are correct about thegreenhouse effect.

a Draw a line graph of these results on the grid.

b As the amount of carbon dioxide increases, thetemperature …

… decreases

… increases

… stays the same.

F6


SpecialsGetting hotter (continued)

3 In an experiment, a scientist measured the amount ofcarbon dioxide in the air. She also measured thetemperature of the air. Here are the results.

Sheet 2 of 2

The firstpoint has beendrawn for you.

Tick thebox to show the

right answer.

0 0.1 0.2 0.3Amount of carbon dioxide in %

0.4 0.520

21

22

23

24

25

Temperaturein °C

�

Amount of Temperature carbon dioxide in % in °C

0.1 20

0.2 21

0.3 22

0.4 23

0.5 24

F1 Changing materials1 a chemical, irreversible

b physical, reversible2 Circles should be around egg frying, fireworks,

candle burning, rusty car.3 Coloured red – There are bubbles, The mixture

does not stay the same temperature, Themixture gives out heat energy, The colourchanges and stays changed, The mixture givesout coloured light, There is a flame.

4 reactants, substances, products

F2 Acids and metals1 bubbles2 a Correct order of numbers is 3, 1, 2.

b give a squeaky pop3 acids, hydrogen, pops4 Oxygen and water circled.

F3 Acids and carbonates1 bubbles2 a Correct order of numbers is 3, 1, 2.

b turn milky3 The reaction is a … neutralisation.

The reactants are … carbonate and acid.A product is … carbon dioxide.

4 a The burning splint could be shown goingout, the limewater turns milky.

b carbon dioxide5 a Chalk, limestone and marble coloured red.

b Acids in the surroundings will slowly wearaway statues made of marble.

F4 Firefighting1 air, oxygen, combustion, fuel, energy2 a air (or oxygen), fuel, energy correctly filled

inb i air/oxygen ii air/oxygen iii energy

iv fuel

F5 Burning changes1 a carbon + oxygen → carbon dioxide

b carbon and oxygen should be coloured red,carbon dioxide should be coloured blue.

2 a oxygen b oxides c oxides3 The following should be coloured red:

carbon + oxygen → carbon dioxidelead + oxygen → lead oxidepetrol + oxygen → carbon dioxide + watermagnesium + oxygen → magnesium oxide

4 a oxide b carbon c sodiumd oxygen e hydrogen

F6 Getting hotter1 fuels – we burn these to get energy

oxygen – this gas is needed for things to burncarbon dioxide and water – these are produced(made) when fuels burncoal, petrol and wood – these are fuels

2 The following should be coloured red:The amount of carbon dioxide in the air isincreasing.Carbon dioxide gas traps the Earth’s heat.The Earth will get hotter if more heat istrapped.

3 a Correctly drawn graph – all the points lie ona straight line from (0.1, 20) to (0.5, 24).

b increases

F Specials answersSimple chemical reactions


F1


HomeworkChanging materials

HELP1 Copy and complete this sentence.

When you mix substances and they change into new substances,

we say that a ...................................... ...................................... has taken place.

2 Here is a list of changes.

Make a table with the headings shown below. Complete it using wordsfrom the list.

3 When water is added to white copper sulphate powder, the powderbecomes hot and turns blue.

There are two reasons why this must be a chemical change. Writethem down.

CORE4 Jenny’s teacher asked her to find out about magnesium. She told Jenny

to mix a small piece of magnesium with some hydrochloric acid. Jennyhad to wear safety spectacles.

When she mixed them, she noticed bubbles coming from themagnesium. Her teacher said that the bubbles were a gas calledhydrogen.

a Write down the names of the two reactants that Jenny used.

b The hydrogen was a new substance made from the magnesium andthe acid. What do we call substances that are made in this way?

c Why did Jenny have to wear safety spectacles for her work?

5 Give two observations that show that a chemical change has happenedwhen you mix two substances together, other than the appearance ofbubbles.

Sheet 1 of 2

a puddle of water evaporating gas burning an egg frying

water freezing a cake baking a car using petrol

A chemical change Not a chemical change

F1


HomeworkChanging materials (continued)

EXTENSION6 When magnesium (a grey metal) reacts with oxygen (a colourless

gas), a new substance called magnesium oxide (a white powder)is formed.

a Give one piece of evidence from the information above thatshows a chemical change has taken place.

b Write a word equation for this chemical reaction.

7 Use this information to answer the question below.

● Copper is a pinkish brown metal.

● Oxygen is a colourless gas.

● Copper oxide is a black solid

Sam heated a pinkish brown solid in a Bunsen burner flame. Itreacted with a gas in the air around it and turned into a blacksolid.

Write a word equation for the chemical reaction that Sam carriedout.

Sheet 2 of 2

F2


HomeworkAcids and metals

HELP1 Hannah mixed some zinc with some sulphuric acid. She observed

bubbles of gas coming from the zinc. Name the gas in the bubbles.

2 Copy and complete these sentences about the test for hydrogen,using the words below.

To test for hydrogen you need a ...................................... splint. Put it at the

...................................... of a test tube of the gas you are testing. If the gas

...................................... with a ...................................... ...................................... then the gas

is ...................................... .

CORE3 a Think about what you see when you add a piece of magnesium to

dilute acid. Write a sentence to explain how you know this must bea chemical reaction.

b Write another sentence to explain how you know that rusting is achemical reaction.

c List the two key substances, other than iron, that must be presentfor rusting to occur.

d Why does covering a bicycle chain with oil help to prevent it fromgoing rusty?

EXTENSION4 Write a word equation showing all the reactants and products to

represent the reaction that takes place when magnesium metal reactswith sulphuric acid.

5 For each of the substances listed below, write down which metal andwhich acid you would use to make it.

a zinc chloride b iron sulphate

c calcium chloride d aluminium sulphate

6 If you were adding zinc metal to sulphuric acid, how would you knowwhen all the acid had all reacted?

Sheet 1 of 1

hydrogensqueaky pop lighted burns mouth

F3


HomeworkAcids and carbonates

HELP1 The diagram shows the apparatus for making carbon dioxide gas.

a Stick down the diagram.

b Label it using the words below.

CORE2 To test a gas to see if it is carbon dioxide, you bubble the gas

through a special solution.

a What is the name of this special solution?

b What happens when you bubble carbon dioxide through it?

3 Here are some statements about what happened when somechemicals were mixed. Write ‘true’ if you think the statement iscorrect. If you think something is wrong, rewrite the statement sothat it is correct. Do not change the underlined part.

a When you mix sulphuric acid with copper carbonate, themixture fizzes.

b Hydrogen gas is formed from a mixture of copper carbonateand sulphuric acid.

c If you test the gas from a mixture of magnesium andhydrochloric acid, it turns limewater milky.

d Sherbet contains an acid and a type of metal carbonate, sowhen it gets wet, it gives off hydrogen gas.

4 Rainwater is naturally acidic. Over a long period of time, buildingsmade from limestone (calcium carbonate rock) slowly weatheraway. Explain why rainwater has this effect on limestone buildings.

5 When you add a small amount of solid magnesium carbonate to alot of hydrochloric, the solid ‘disappears’. Write a sentence toexplain where it goes.

Sheet 1 of 3

delivery tubecalcium carbonatehydrochloric acid

carbon dioxide limewater

F3


HomeworkAcids and carbonates (continued)

EXTENSION6 Copy and complete the table, which is about the products formed

during different chemical reactions.

7 Nitric acid is another common acid. When it reacts with a metalcarbonate, you see the same things that you see usinghydrochloric acid. However, nitric acid gives nitrates instead ofchlorides.

Write a word equation to represent the reaction that would takeplace if you mixed zinc carbonate with dilute nitric acid.

Sheet 2 of 3

Reactant 1 Reactant 2 Product 1 Product 2 Product 3

hydrochloric acid zinc metal hydrogen

sodium carbonate sulphuric acid water

hydrochloric acid copper carbonate water

F3


HomeworkAcids and carbonates (continued)

HELPApparatus for making carbon dioxide gas

Sheet 3 of 3

HELPApparatus for making carbon dioxide gas

F3 Homework

✂

Acids and carbonates (continued)


F4


HomeworkFirefighting

HELP1 Copy and complete these sentences.

When a substance burns, it reacts with the gas called ......................................

in the air. Another name for a burning reaction is .......................................

Three things are needed for burning. They are shown in the fire

.......................................

2 Copy the fire triangle below. Add the labels that are missing from two ofthe sides.

CORE3 When firefighters put out a fire, they remove one or two sides of the fire

triangle. Copy and complete the sentences below to show which side orsides of the fire triangle are being removed.

a Spraying water onto a burning house puts out the fire because …

b Rolling a burning person in a fire blanket puts out the fire because …

c Turning off the Bunsen burner at the gas tap puts out the fire because …

d A charcoal barbecue eventually goes out on its own because …

e After the flames have gone out from a burning house, the firefighterskeep on spraying water onto the house because …

Sheet 1 of 2

ener

gy

F4


HomeworkFirefighting (continued)

EXTENSION4 Propane (substance A) is a fuel. It burns in oxygen (substance B)

to form two new substances. One of them (substance C) is a gas,which turns limewater milky. The other (substance D) at firstappears as a colourless gas, but when cooled it condenses into acolourless liquid that boils at 100 °C.

a Write down the names of substance C and substance D.

b Write a word equation to represent the combustion of propane.

c If you cooled down substance D, at what temperature would itform a solid?

Sheet 2 of 2

F5


HomeworkBurning changes

HELP1 Copy and complete these sentences.

When fireworks burn in air, they are reacting with the gas .......................................

When magnesium burns in oxygen, it forms a white powder called

magnesium ...................................... .

Black copper oxide forms when copper metal is ...................................... in air.

2 A grey metal powder was sprinkled into a Bunsen burner flame. It glowedvery brightly. A white powder formed.

Use the information above to help you answer these questions.

a What tells you that the metal probably burned in the Bunsen flame?

b Why is the white powder probably a metal oxide?

CORE3 Here is a word equation for the

combustion reaction of magnesium:

Write a word equation for these reactions:

a copper reacting with oxygen to form copper oxide

b carbon reacting with oxygen to form carbon dioxide

c sodium burning in air.

4 In an experiment, equal-sized pieces of phosphorus were placed into eachof two gas jars A and B. The phosphorus burst into flames and burned inboth jars. It burned brighter and for a longer time in jar A than in jar B.

a What can you deduce that was similar about the gas in both jars?

b Explain how you reached your answer to part a.

c In what way do you think the gas in the jars might have been different?

d Explain why you think it was different.

5 Copy and complete these word equations for combustion reactions.

a ...................................... + oxygen _ iron oxide

b hydrogen + oxygen _ ...................................... (Hint: not hydrogen oxide.)

Sheet 1 of 2

magnesium + oxygen _ magnesium oxide

F5


HomeworkBurning changes (continued)

EXTENSION6 Here is the reaction between sulphur and oxygen, shown as a

‘particle picture’.

a i Explain why the particles shown in the picture can bedescribed as ‘balanced’.

ii Explain how you can tell, from the particle picture only, thata chemical reaction has taken place.

iii If represents sulphur and represents oxygen, suggesta suitable name for the product.

b Here is the word equation for the formation of water fromhydrogen and oxygen:

hydrogen + oxygen _ water

Draw a particle picture version of the equation, starting withhydrogen. This is a hard question, so take your time to thinkabout it.

Sheet 2 of 2

S O O� O OS

H HThe particle picture for hydrogen is

The particle picture for oxygen is O O

H HThe particle picture for water is O

S O

F1


Homeworkmark schemeChanging materials

Sheet 1 of 5

Question Answer Mark

1 Chemical reaction or chemical change 1

2 A chemical change: an egg frying, gas burning, a car using petrol, a cake bakingNot a chemical change: a puddle of water evaporating, water freezingOne mark for each correct answer. 6

3 The powder became hot or gave out energy. 1The powder turned blue or changed colour. 1

Total for Help 9

HELP


4 a Magnesium and hydrochloric acidOne mark for both. 1

b Products 1

c Because hydrochloric acid is corrosive or irritant or can damage the eyes 1

5 Two from: a colour change; a substance being used up; a substance being formed; energy being given out or taken in or sound, light or heat being given out 2

Total for Core 5

CORE


6 a A new substance is formed which looks different or there was a colour change. 1

b Magnesium + oxygen → magnesium oxideOne mark for reactants; one mark for products. 2

7 Copper + oxygen → copper oxideOne mark for reactants; one mark for products. 2

Total for Extension 5

EXTENSION

F2


Homeworkmark schemeAcids and metals

Sheet 2 of 5


1 Hydrogen 1

2 To test for hydrogen you need a lighted splint. Put it at the mouth of a test tube of the gas you are testing. If the gas burns with a squeaky pop then the gas is hydrogen. 4Underscores show answers; other text copied by pupils. Deduct one mark for each error up to four.

Total for Help 5

HELP


3 a The mixture gives off bubbles or effervesces or gives off a gasor magnesium is used up. 1

b The iron changes colour or goes red. 1

c Water 1Air or oxygen 1

d The oil prevents air or oxygen and/or water from reaching the iron. 1Accept equivalent answers.

Total for Core 5

CORE


4 Magnesium + sulphuric acid → magnesium sulphate + hydrogen 2One mark for reactants; one mark for products.

5 a Zinc and hydrochloric acid 1

b Iron and sulphuric acid 1

c Calcium and hydrochloric acid 1

d Aluminium and sulphuric acid 1

6 The mixture would stop bubbling although there was still some zinc left. 1Accept equivalent answers.


EXTENSION

F3


Homeworkmark schemeAcids and carbonates

Sheet 3 of 5


1 a, b Clockwise from top: delivery tube, carbon dioxide, limewater, calcium carbonate,hydrochloric acid 3All correct, three marks; three or four correct, two marks; one or two correct, one mark.

Total for Help 3

HELP


2 a Limewater 1

b It goes cloudy or milky. 1

3 a True 1

b Carbon dioxide gas is formed from a mixture of copper carbonate and sulphuric acid. 1

c If you test the gas from a mixture of magnesium carbonate and hydrochloric acid, it turns limewater milky. 1

d Sherbet contains an acid and a type of metal carbonate, so when it gets wet, it gives off carbon dioxide gas. 1

4 Acids react with (metal) carbonates 1so the rainwater reacts with or dissolves away some of the limestone. 1

5 The solid has reacted and is now in the solution or carbon dioxide gas is formed. 1

Total for Core 9

CORE


6 Hydrochloric acid and zinc: product 2 is zinc chloride. 1Sodium carbonate and sulphuric acid: products 1 and 2 are carbon dioxide and sodium sulphate (in any order). 1Hydrochloric acid and copper carbonate: products 1 and 2 are carbon dioxide and copper chloride (in any order). 1

7 Zinc carbonate + nitric acid → zinc nitrate + carbon dioxide + water 2One mark for reactants; one mark for products.


EXTENSION

F4


Homeworkmark schemeFirefighting

Sheet 4 of 5


1 When a substance burns, it reacts with the gas called oxygen in the air. 1Another name for a burning reaction is combustion. 1Three things are needed for burning. They are shown in the fire triangle. 1Underscores show answers; other text copied by pupils.

2 Fuel and oxygen added to the fire triangle. 2

Total for Help 5

HELP


3 a Spraying water onto a burning house puts out the fire because it removesenergy or cools it down. 1

b Rolling a burning person in a fire blanket puts out the fire because it removes air or oxygen. 1

c Turning off the Bunsen burner at the gas tap puts out the fire because it removes the fuel supply. 1

d A charcoal barbecue eventually goes out on its own because it runs out of fuel. 1

e After the flames have gone out from a burning house, the firefighters keep on spraying water onto the house because the fuel is still hot so it mightre-ignite or start burning again.Underscores show answers; other text copied by pupils. 1

Total for Core 5

CORE


4 a C is carbon dioxide 1D is water 1

b Propane + oxygen → carbon dioxide + water 1One mark for reactants; one mark for products. 1

c 0 °C 1


EXTENSION

F5


Homeworkmark schemeBurning changes

Sheet 5 of 5


1 When fireworks burn in air, they are reacting with a gas called oxygen. 1When magnesium burns in oxygen, it forms a white powder called magnesium oxide. 1Black copper oxide forms when copper metal is heated or burned in air.Underscores show answers; other text copied by pupils. 1

2 a It glowed. 1

b It reacted with oxygen in the air or metals form oxides when they burnor the product of combustion is an oxide. 1

Total for Help 5

HELP


3 a Copper � oxygen → copper oxide 1

b Carbon � oxygen → carbon dioxide 1

c Sodium � oxygen → sodium oxide 1

4 a Both contained oxygen. 1

b Oxygen must have been present for phosphorus to ignite or burn.Accept equivalent answers. 1

c There was more oxygen in jar A than in jar B. 1

d Phosphorus burned brighter and for longer. 1Add one mark for good quality of communication in parts 4b to d. 1

5 a Iron � oxygen → iron oxide 1

b Hydrogen � oxygen → waterUnderscores show answers; other text copied by pupils. Do not accept variations on hydrogen oxide. 1

Total for Core 10

CORE


6 a i There are the same numbers of particles on both sides. 1Accept equivalent answers.

ii The particles are now all joined together or there is only one particle. 1Accept equivalent answers.

iii Sulphur dioxide 1Do not accept sulphur oxide.

b Accept appropriate particle pictures 1with the numbers of particles balanced on each side of the equation. 1


EXTENSION

Sheet 1 of 1

F


Transition quiz

1 Your friend Sam cannot do her homework.

Which of the following processes are reversible changes and which are non-reversible changes?

Write a tick (�) if you think it is a reversible change and a cross (�) if you think it is non-reversible.

a A chocolate melting in your hand.

b A snowman melting in the sun.

c A bicycle going rusty.

d A beaker of water evaporating.

e A firework exploding.

2 Complete these sentences using the words below.

a Burning a match is an example of a ...................................... ...................................... .

b Ice becoming water is an example of a ...................................... ...................................... .

Simple chemical reactions

reversible reaction non-reversible reaction

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Transitionworksheet

1 Using the words in the box below, how many sentences can youmake to show what you understand by reversible and non-reversible changes?

Underline the words used from the box in each sentence you make.

One has been started for you.

When burning wood produces new materials, this is an example of a

............................................................................ .

.................................................................................................................................................................

.................................................................................................................................................................

.................................................................................................................................................................

.................................................................................................................................................................

.................................................................................................................................................................

.................................................................................................................................................................

2 Sima was copying some work from the board. Unfortunately she didnot have time to complete the diagram before the teacher rubbed itoff. Can you help her by labelling the diagram for her?


heating cooling dissolving melting freezing

solid evaporating condensing burning change

reversible non-reversible salt water wood

wax gas steam new material ice

F


Test yourselfSimple chemical reactions

1 Tick the changes that are chemical changes.

A piece of wood burns.

An ice cube melts.

Two substances are mixed and bubbles form.

Water evaporates from a puddle.

Heat is given out when two substances are mixed.

Two substances are mixed and the mixture feels cold.

Two substances are mixed and the mixture turns green.

A mixture of two substances smells revolting.

2 Draw lines to match the reactants to the gas that is producedwhen they react.

Reactants Gas

hydrochloric acid � zinc metal ●

sulphuric acid � calcium carbonate ●

nitric acid � sodium metal ● ● carbon dioxide

citric acid � sodium carbonate ● ● hydrogen

phosphoric acid � iron ●

tartaric acid � potassium carbonate ●

3 The statements are about making and testing hydrogen gas. Put them in order by writing numbers in the boxes.

Wait until the reaction has finished.

Put 2 cm depth of hydrochloric acid into a test tube.

Hold a burning splint at the mouth of the test tube.

Put a bung loosely into the test tube.

If the gas burns with a pop, it is hydrogen.

Add one piece of magnesium ribbon to the acid.

Remove the bung.

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Test yourselfSimple chemical reactions (continued)

4 Write true or false for each statement.

a Hydrogen gas burns with a pop. ................................

b Carbon dioxide gas burns with a pop. ................................

c Carbon dioxide gas turns limewater milky. ................................

d Acids react with metals to make carbon dioxide gas. ................................

e Acids react with carbonates to make carbon dioxide gas. ................................

f Acids react with metals to make hydrogen gas. ................................

g Acids react with carbonates to make hydrogen gas. ................................

5 Complete these sentences by crossing out the wrong words.

Fuels burn in air because air contains nitrogen/oxygen/other gases.Fuels need energy/water to start them burning.

Charcoal is a fuel/gas made from carbon/hydrogen. When it burns,the reaction is called combustion/condensation. The product of thereaction is hydrogen/water/carbon dioxide.

6 Complete these word equations.

a iron + oxygen → ........................................................

b magnesium + oxygen → ........................................................

c carbon + oxygen → ........................................................

d zinc + oxygen → ........................................................

e sulphur + oxygen → ........................................................

f hydrogen + oxygen → ........................................................

7 A candle is mainly made of carbon and hydrogen. What two substanceswill be made when a candle burns in air?

..................................................................................................................................................................................

Sheet 2 of 3

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Test yourselfSimple chemical reactions (continued)

8 Complete the fire triangle by writing in the three things that a fireneeds to keep burning.

9 Use the fire triangle to write down what has been removed to makethese fires go out.

a Water is sprayed on a fire. ................................................................................ .

b Trees are cut down to stop a forest fire spreading.

................................................................................. .

c A fire blanket is put over a fire. ................................................................................. .

d A damp cloth is spread over a chip pan fire.

.................................................................................................. .

Sheet 3 of 3

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Test yourselfAnswersSimple chemical reactions

1 Tick the changes that are chemical changes.

A piece of wood burns.

An ice cube melts.

Two substances are mixed and bubbles form.

Water evaporates from a puddle.

Heat is given out when two substances are mixed.

Two substances are mixed and the mixture feels cold.

Two substances are mixed and the mixture turns green.

A mixture of two substances smells revolting.

2 Draw lines to match the reactants to the gas that is producedwhen they react.

Reactants Gas

hydrochloric acid � zinc metal ●

sulphuric acid � calcium carbonate ●

nitric acid � sodium metal ● ● carbon dioxide

citric acid � sodium carbonate ● ● hydrogen

phosphoric acid � iron ●

tartaric acid � potassium carbonate ●

3 The statements are about making and testing hydrogen gas. Put them in order by writing numbers in the boxes.

Wait until the reaction has finished.

Put 2 cm depth of hydrochloric acid into a test tube.

Hold a burning splint at the mouth of the test tube.

Put a bung loosely into the test tube.

If the gas burns with a pop, it is hydrogen.

Add one piece of magnesium ribbon to the acid.

Remove the bung.5

2

7

3

6

1

4

�

�

�

�

�

�

Sheet 1 of 3

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Test yourselfAnswersSimple chemical reactions (continued)

4 Write true or false for each statement.

a Hydrogen gas burns with a pop. ................................

b Carbon dioxide gas burns with a pop. ................................

c Carbon dioxide gas turns limewater milky. ................................

d Acids react with metals to make carbon dioxide gas. ................................

e Acids react with carbonates to make carbon dioxide gas. ................................

f Acids react with metals to make hydrogen gas. ................................

g Acids react with carbonates to make hydrogen gas. ................................

5 Complete these sentences by crossing out the wrong words.

Fuels burn in air because air contains nitrogen/oxygen/other gases.Fuels need energy/water to start them burning.

Charcoal is a fuel/gas made from carbon/hydrogen. When it burns,the reaction is called combustion/condensation. The product of thereaction is hydrogen/water/carbon dioxide.

6 Complete these word equations.

a iron + oxygen → ........................................................

b magnesium + oxygen → ........................................................

c carbon + oxygen → ..........................................................................................................

d zinc + oxygen → ........................................................

e sulphur + oxygen → ........................................................

f hydrogen + oxygen → ........................................................

7 A candle is mainly made of carbon and hydrogen. What two substanceswill be made when a candle burns in air?

..................................................................................................................................................................................

Sheet 2 of 3

true

false

true

false

true

true

false

iron oxide

magnesium oxide

carbon dioxide / carbon monoxide

zinc oxide

sulphur dioxide

water

carbon dioxide and water

F


Test yourselfAnswersSimple chemical reactions (continued)

8 Complete the fire triangle by writing in the three things that a fire needs to keep burning.

9 Use the fire triangle to write down what has been removed to makethese fires go out.

a Water is sprayed on a fire. ................................................................................ .

b Trees are cut down to stop a forest fire spreading.

................................................................................. .

c A fire blanket is put over a fire. ................................................................................. .

d A damp cloth is spread over a chip pan fire.

.................................................................................................. .

Sheet 3 of 3

fueloxygen

energy

Energy has been removed

Oxygen or energy has been removed

Oxygen has been removed

Fuel has been removed

F


End of unit testGreenSimple chemical reactions

1 Write down two things that are needed to allow a fuel to burn. 2 marks

2 Copy and complete these sentences by choosing from the words in bold.

a Water changing to steam is/is not a chemical change. 1 mark

b Wood burning to ash is/is not a chemical change. 1 mark

c Iron changing to rust is/is not a chemical change. 1 mark

3 When Robert mixes hydrochloric acid and a lump of rock, a gas is given off which turns limewater milky.

Write down the statement that is most correct. 1 mark

● Nothing has changed.

● This might be a chemical change.

● This is a definitely a chemical change.

● This is definitely not a chemical change.

4 Copy and complete these sentences, choosing from the words below.

a ...................................... is very flammable. 1 mark

b ...................................... does not burn. 1 mark

Sheet 1 of 3

oxygen carbon dioxidehydrogen nitrogen

F


End of unit testGreenSimple chemical reactions (continued)

5 Pamela carried out four experiments. She mixed two substances each time. Here are her observations.

● Experiment 1: The tube felt warmer to the touch.

● Experiment 2: The mixture fizzed.

● Experiment 3: The tube felt colder to the touch.

● Experiment 4: There was a smell like a baby’s wet nappy.

For each experiment, write down whether there was definitely a chemical change, possibly a chemical change or no chemical change. 4 marks

6 Jo added hydrochloric acid to a white powder. A chemical change took place and a gas was given off that turned limewater milky.

a What was the gas that was formed? Choose from the words below. 1 mark

b What is the white powder? Choose from the words below. 1 mark

c Explain how you decided on your answer to b. 1 mark

Jo then added hydrochloric acid to some powdered magnesium metal. The mixture fizzed and a different gas was released that burned with a squeaky pop.

d What is the name of the gas made during this reaction? 1 mark

e Jo has collected samples of three different gases in test tubes. She has labelled them A, B and C. She tests each one in turn with a lighted splint. The table below shows the results. What are A, B and C? 3 marks

Sheet 2 of 3

Gas Result

A Pops with a lighted splint

B Lighted splint goes out

C Lighted splint burns more brightly

oxygen carbon dioxide hydrogen nitrogen

calcium carbonatecalcium sulphatesodium chloride

F


End of unit testGreenSimple chemical reactions (continued)

7 Patel’s mum has set the chip pan on fire. Patel tells her to put a damp tea towel over the pan, turn off the cooker and let the pan cool down.

The damp tea towel makes the fire go out by stopping something from getting to the fire. What is this something? 1 mark

8 Amy is investigating the effects of acid on powdered magnesium metal.

a Which apparatus below should she use to measure the acid most precisely? Write the correct letter. 1 mark

b Name the apparatus you have chosen. 1 mark

c Amy has been studying three types of chemical reaction, and she says that she can see patterns in them. Copy and complete her table to show what she has discovered. 3 marks

Sheet 3 of 3

A B C D

Chemical reaction Substance made

acids reacting with metals

materials burning

acids reacting with carbonates

F


End of unit testRedSimple chemical reactions

1 Copy and complete these sentences, choosing from the words below.

a ...................................... is very flammable. 1 mark

b ...................................... does not burn. 1 mark

2 Pamela carried out four experiments. She mixed two substances each time. Here are her observations.

● Experiment 1: The tube felt warmer to the touch.

● Experiment 2: The mixture fizzed.

● Experiment 3: The tube felt colder to the touch.

● Experiment 4: There was a smell like a baby’s wet nappy.

For each experiment, write down whether there was definitely a chemical change, possibly a chemical change or no chemical change. 4 marks

3 Patil burned some methane in the apparatus shown. Carbon dioxide was made, and one other gas. What was the other gas? 1 mark

4 Copy and complete these sentences.

a When carbon burns in oxygen, ...................................... is made. 1 mark

b When iron reacts with oxygen, ...................................... is made. 1 mark

Sheet 1 of 3

oxygen carbon dioxidehydrogen nitrogen

Bunsen burner

air drawnthrough

limewater

F


End of unit testRedSimple chemical reactions (continued)

5 Jo added hydrochloric acid to a white powder. A chemical change took place and a gas was given off that turned limewater milky.

a What was the gas that was formed? Choose from the words below. 1 mark

b What is the white powder? Choose from the words below. 1 mark

Jo then added hydrochloric acid to some powdered magnesium metal. The mixture fizzed and a gas was released.

c What is the name of the gas made during this reaction? 1 mark

d What test should Jo use to prove that this gas had been made? 2 marks

e Jo has collected samples of three different gases in test tubes. She has labelled them A, B and C. She tests each one in turn with a lighted splint. The table below shows the results. What are A, B and C? 3 marks

6 Eileen burns some magnesium in air. A white powder is left behind.

a What is the name of this white powder? 1 mark

b Write a word equation for magnesium burning. 2 marks

Sheet 2 of 3

oxygen carbon dioxide hydrogen nitrogen

calcium carbonatecalcium sulphatesodium chloride

Gas Result

A Pops with a lighted splint

B Lighted splint goes out

C Lighted splint burns more brightly

F


End of unit testRedSimple chemical reactions (continued)

7 a Amy has been studying three types of chemical reaction, and she says that she can see patterns in them. Copy and complete her table to show what she has discovered. 3 marks

b Amy is planning to investigate the burning of a candle in air. She plans to weigh the candle before and after burning. Why does she want to do this? 1 mark

c She plans to hold an upturned beaker above the candle flame for a while. She thinks water is produced when a candle burns. What might she see in the upturned beaker? 1 mark

Sheet 3 of 3

Chemical reaction Substance made

acids reacting with metals

materials burning

acids reacting with carbonates

F


End of unit testmark schemeSimple chemical reactions

Sheet 1 of 1

Green (NC Tier 2–5)

Scores in the range of: NC Level

4–7 2

8–13 3

14–17 4

18–25 5

Question Answer Mark Level

1 Energy or heat; oxygen or air 1, 1 2

2 a Water changing to steam is not a chemical change. 1 3

b Wood burning to ash is a chemical change. 1 3

c Iron changing to rust is a chemical change. 1 3Italics show answers; other text copied by pupils.

3 This is definitely a chemical change. 1 3

4 a Hydrogen is very flammable. 1 3

b Oxygen or carbon dioxide or nitrogen does not burn. 1 3Italics show answers; other text copied by pupils.

5 1 definitely or possibly a chemical change 1 42 definitely a chemical change 1 43 definitely or possibly a chemical change 1 44 definitely a chemical change 1 4

6 a Carbon dioxide 1 4

b Calcium carbonate 1 4

c Because carbonates react with acids to make carbon dioxide 1 5

d Hydrogen 1 4

e A hydrogen 1 4B carbon dioxide or nitrogen 1 4C oxygen 1 5

7 Oxygen or air 1 4

8 a D 1 3

b Measuring cylinder 1 3

c Acids reacting with metals: hydrogen 1 4Materials burning: oxides 1 4Acids reacting with carbonates: carbon dioxide 1 4

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End of unit testmark schemeSimple chemical reactions

Sheet 1 of 1

Red (NC Tier 3–6)

Scores in the range of: NC Level

4–8 3

9–14 4

15–18 5

19–25 6

Question Answer Mark Level

1 a Hydrogen is very flammable. 1 3

b Oxygen or carbon dioxide or nitrogen does not burn. 1 3Italics show answers; other text copied by pupils.

2 1 definitely or possibly a chemical change 1 42 definitely a chemical change 1 43 definitely or possibly a chemical change 1 44 definitely a chemical change 1 4

3 Water (vapour) 1 4

4 a When carbon burns in oxygen, carbon dioxide is made. 1 5

b When iron reacts with oxygen, iron oxide is made. 1 5Italics show answers; other text copied by pupils.

5 a Carbon dioxide 1 4

b Calcium carbonate 1 4

c Hydrogen 1 5

d Test with a burning splint. 1 5Hydrogen burns with a (squeaky) pop. 1 5

e A hydrogen 1 4B carbon dioxide or nitrogen 1 4C oxygen 1 5

6 a Magnexium oxide 1 5

b Magnesium � oxygen → magnesium oxide. One mark for reactants; one mark for products. 2 6

7 a Acids reacting with metals; hydrogen 1 4Materials burning: oxides 1 4Acids reacting with carbonates: carbon dioxide 1 4

b To see if its mass changes 1 5

c Water droplets or condensation 1 5

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Pupil check listSimple chemical reactions

Learning outcomes I can do I can do I need tothis very this quite do more well well work on this

I can classify a given example as being a physical or chemical change/reaction and say why.

I can state the observations which identify a chemical change.

I can recognise examples of chemical changes taking place around us every day.

I can make observations and see patterns from results.

I can predict what is likely to happen if a metal is added to an acid.

I can describe and carry out the chemical test for hydrogen.

I can predict what is likely to happen if a carbonate is added to an acid.

I can describe and carry out the chemical test for carbon dioxide.

I can explain what combustion is.

I can use the fire triangle to explain why firefighting stops fires.

I can describe evidence to show that part of the air is used up during burning.

I can name the variables I am working with in an investigation.

I can describe the pattern in data obtained from burning candles in air.

I can explain how oxides are formed in burning reactions.

I can identify the reactants and products in a word equation.

I can write a word equation to show what takes place when metals burn in oxygen.

I can describe how scientists use models to test their ideas about the greenhouse effect.

I can identify variables in investigations and look for relationships in data.

Sheet 1 of 2

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Glossary

Word

acid rain R

carbonates

carbon dioxide

charcoal

chemical change

chemical reaction

chlorides R

combustion

corrosion

fire triangle

fuel

greenhouse effect

hydrocarbons R

hydrogen

input variable

irreversible change

lethal R

limewater

methane R

model R

neutralisation

outcome variable

oxide

oxygen

physical change

products

reactants

relationship

Definition

Something that can be changed back to how it wasbefore.

Something that cannot be changed back to how it wasbefore.

A change in which no new substance is made. Achange of state is a physical change. Physical changesare reversible.

A change that makes a new substance. Many chemicalchanges are irreversible.

A change that makes a new substance.

The new substances that are formed in a chemicalreaction.

The substances that take part in a chemical reaction,and change into the products.

An equation in words to show a chemical reaction.

An explosive gas.

Eating away of the surface of a solid by a chemicalreaction.

The chemical reaction that takes place when an acidreacts with a base.

Substances that are formed when sulphuric acid isneutralised. R

A gas that is produced when carbon burns and joinswith oxygen, or when a carbonate reacts with an acid.Carbon dioxide turns limewater milky.

A solution used to test for carbon dioxide. Limewaterturns milky when carbon dioxide bubbles through it.

Substances that react with acid to produce carbondioxide. Many rocks are made of carbonates.

Substances that are formed when hydrochloric acid isneutralised. R

Rain polluted by acidic gases dissolved in it. Acid rain ismore acidic than rainwater that is not polluted. R


Sheet 2 of 2

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Glossary

Word

reversible change

sulphates R

toxic R

word equation

Definition

A gas. Oxygen is used in burning and in respiration.

A material that has a lot of stored chemical energy. Weburn a fuel to use the energy.

The chemical reaction that happens when somethingburns.

A way of showing the three things a fire needs to burn– fuel, oxygen and energy.

A fuel made from wood, that is mainly carbon.

An oxide is made when a substance burns and joinswith oxygen from the air.

Fuels that are made up of carbon and hydrogen. R

A hydrocarbon fuel that is a gas. Natural gas is mainlymethane. R

Toxic means poisonous. Substances that may causeserious health risks and even death if inhaled, takeninternally or absorbed through the skin are toxic. R

Something that is lethal can kill. R

The carbon dioxide in the air stops some of the heatenergy escaping from Earth so making the Earthwarmer. It behaves like the glass in a greenhouse.

The thing you change in an investigation.

The thing that changes during an investigation. Theoutcome variable is the thing you measure.

A pattern that links variables together. A relationshipdescribes how the outcome variable changes when theinput variable is changed.

An idea or picture made up by a scientist to show asituation that cannot be seen. A model helps scientiststhink through explanations. R

Simple chemical reactions (continued)

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F


Key wordsSimple chemical reactions

acid rain R

carbonates

carbon dioxide

charcoal

chemical change

chemical reaction

chlorides R

combustion

corrosion

fire triangle

fuel

greenhouse effect

hydrocarbons R

hydrogen

input variable

irreversible change

lethal R

limewater

methane R

model R

neutralisation

outcome variable

oxide

oxygen

physical change

products

reactants

relationship

reversible change

sulphates R

toxic R

word equation

F Key words

�



acid rain R

carbonates

carbon dioxide

charcoal

chemical change

chemical reaction

chlorides R

combustion

corrosion

fire triangle

fuel

greenhouse effect

hydrocarbons R

hydrogen

input variable

irreversible change

lethal R

limewater

methane R

model R

neutralisation

outcome variable

oxide

oxygen

physical change

products

reactants

relationship

reversible change

sulphates R

toxic R

word equation

F1 Changing materialsGreena Physical – freezing ice, melting an ice lolly;

chemical – cooking a burger, burning charcoal.b If a new substance is made, a chemical

reaction has happened.c Any three from: gas or light given out; colour

change, heat given out or taken in.d i reactants

ii products1 Burning a match is a chemical reaction. It is

an irreversible change. The wood is used upand new substances are made. Energy is givenout as heat and light.

2 Light and heat are given out. The originalsubstance is used up.

Reda i Melting ice, freezing water, boiling water,

melting wax, etc.ii Burning coal, cooking anything, etc.

b The wood has turned black and is no longerwood; light and heat have been given out.

c i Iron and sulphur.ii Iron sulphide.

iii Any three from: heat was given out, lightwas given out, a colour change occurred,the magnetic property of the iron was lost.

1 a Light and heat were given out.b Iron was used up, oxygen was used up, a

new substance was formed.c Iron and oxygen.d Iron oxide.e Iron + oxygen → iron oxide.

2 Yes. A new solid substance is being formed andthere is a colour change.

F2 Acids and metalsGreena The zinc is used up and bubbles are formed.b Zinc and sulphuric acid.c Hydrogen and zinc sulphate.d Hydrogene Put the lighted splint near the top of the test tube.1 Some metals react with acids to make

hydrogen. We test for hydrogen using alighted splint. A pop means it is hydrogen.

2 Put a lighted splint near the top of the test tubeyou think contains hydrogen. If you hear a‘pop’, then the gas was hydrogen.

Reda The zinc is used up and bubbles are formed.b i Zinc and sulphuric acid.

ii Hydrogen and zinc sulphate.c Sulphuric acid + zinc

→ hydrogen + zinc sulphate.

d Hydrochloric acid + zinc → hydrogen + zinc chloride

e Hydrochloric acid + aluminium → hydrogen + aluminium chloride

1 Put a lighted splint near the top of the test tubeyou think contains hydrogen. If you hear a‘pop’, then the gas was hydrogen.

2 a Hydrogen and iron sulphateb Iron + sulphuric acid

→ hydrogen + iron sulphate.3 a Zinc sulphate was changed from a solution

to a solid. It could be changed back byadding water.

b 1. Zinc put into sulphuric acid produceshydrogen and zinc sulphate. The zincdisappears and bubbles of hydrogen gas areformed.2. Zinc put into hydrochloric acid formshydrogen and zinc chloride. The zincdisappears and bubbles of hydrogen gas areformed.3. Aluminium put into hydrochloric acidforms hydrogen and aluminium chloride.The aluminium disappears and bubbles ofhydrogen gas are formed. 4. Magnesium put into hydrochloric acidforms hydrogen and magnesium chloride.The magnesium disappears and bubbles ofhydrogen gas are formed. Accept also the reactions of aluminium andmagnesium with sulphuric acid.

4 a When metals are used up by chemicalreactions we call it corrosion.

b The metal is no longer strong and cannot beused for the purpose it was intended.

F3 Acids and carbonatesGreena Bubbles of gas are formed and the chalk is used

up.b i The hydrogen ‘pops’.

ii The splint goes out.c A chemical reaction.d Carbon dioxide gas.1 a Calcium carbonate, limestone, marble or

chalk.b Calcium carbonate and hydrochloric acid.c Carbon dioxide or calcium chloride.

2 Put a test tube into a tube containing what youthink is carbon dioxide. The splint will go out.

3 Marble is a form of calcium carbonate. Thestatues made of marble are wearing awaybecause of acids in the rain.

Reda i Bubbles of gas are formed and the chalk is

used up.ii The limewater turns cloudy.

F Book answersSimple chemical reactions


b Calcium carbonate + hydrochloric acid → carbon dioxide + calcium chloride + water.

c i Lemon juice contains acid. This acid reactswith the carbonate in the ‘bicarb’ toproduce carbon dioxide gas. The gas fluffsup the dough and makes the bread lighter.

ii Sour milk contains acid. This acid reactswith the carbonate in the ‘bicarb’ toproduce carbon dioxide gas. The gas fluffsup the dough and makes the bread lighter.

1 Put a lighted splint into each of the test tubes.The gas in the tube containing hydrogen will‘pop’. The gas in the tube containing carbondioxide will put the splint out. In the tubecontaining air, the splint will continue to burn.

2 a Sodium carbonate + hydrochloric acid → carbon dioxide + sodium chloride.

b Calcium carbonate + sulphuric acid → carbon dioxide + calcium sulphate.

c Zinc + hydrochloric acid → hydrogen + zinc chloride.

3 Heat the solution containing calcium chloride.The water will evaporate leaving the solidcalcium chloride.

4 Malachite is copper carbonate. She might spill adrop of acid on her ring and the air in thechemical laboratory might be slightly acidic,which would react with the malachite in herring and damage it irretrievably.

F4 FirefightingGreena The candle in the largest jar.b Oxygenc 21%d Oxygene The carbon dioxide gas replaces the air around

the fire.1 Burning is a chemical reaction, also called

combustion. Fuel and oxygen are used upduring burning. To get a fire going you alsoneed a spark.

2 The fire has used up a lot of the oxygen.3 a The ‘firebreak’ removes the source of fuel

from the fire.b Soaking the fuel in the fire with water

prevents the heat from catching the fuelalight.

c Covering the fire with a blanket keepsoxygen from the fire which is needed if itwas to continue burning.

Reda The more air there is, the more oxygen there is,

which means the candle can burn longer.b 21%c About 50 seconds.

1 Oxygen is used up and the fuel changes intodifferent substances or disappears.

2 a The ‘firebreak’ removes the source of fuelfrom the fire.

b The carbon dioxides replaces the air/oxygenaround the fire.

c Covering the fire with a blanket keepsoxygen from the fire which is needed if itwas to continue burning.

d Soaking the fuel in the fire with waterprevents the heat from catching the fuelalight.

3 a The wax melts to a liquid. This is reversedwhen the flame goes out and the waxhardens back into a solid.

b Wax is combining with oxygen to produceanother substance. The wax is used up andheat and light are produced.

F5 Burning changesGreena i Carbon and oxygen.

ii Carbon dioxide.iii A chemical reaction occurs.

b Magnesium oxide.c They all contain oxygen.d Copper + oxygen → copper oxide.1 Magnesium + oxygen → magnesium oxide.

Carbon + oxygen → carbon dioxide.Sulphur + oxygen → sulphur dioxide.

2 Iron oxide.3 a Zinc + oxygen → zinc oxide.

b Calcium + oxygen → calcium oxide.c Hydrogen + oxygen → water.

Reda They all contain oxygen.b Propane + oxygen → carbon dioxide + water.c Copper + oxygen → copper oxide.d Aluminium oxide. Aluminium + oxygen

→ aluminium oxide.1 a It can kill you.

b When the amount of oxygen is limited.c To ensure that the lethal carbon monoxide

is not produced.2 a Oxides are made when something is

burned.b Hydrocarbons burn to make carbon

dioxide and water.c Carbonates neutralise acids and make

carbon dioxide.d Metals neutralise acids and make hydrogen.e When sulphuric acid is neutralised you

make sulphates.f When hydrochloric acid is neutralised you

make chlorides.

F Book answers


3 a Zinc + oxygen → zinc oxide.b Magnesium + hydrochloric acid → hydrogen

+ magnesium chloride.c Ethane + oxygen → carbon dioxide + water.

F6 Getting hotterGreena Carbon dioxide in the atmosphere.b Because it keeps the heat in like a greenhouse.c As the amount of carbon dioxide increases the

Earth gets hotter.d The greenhouse effect would be reduced and

the Earth would stop getting hotter.e Carbon dioxide.f Temperature.1 a Both the carbon dioxide level and the

temperature in the biodome increased overthe five days.

b As the carbon dioxide level increased, thetemperature became higher.

2 Individual answers.

Reda Input variable is carbon dioxide; output

variable is temperature.b 22°C1 28°C2 Yes. The ‘greenhouse’ effect of carbon dioxide

keeping heat around the Earth has been shownby scientists to be a fact.

3 The temperature of the Earth will increase overthe next 10 years.

4 Reduce the burning of fuels containing carbon.5 a Would melt.

b Would become warmer.c Would decrease because of flooding from

melting polar caps.

F Book answers


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