Section 1: ChemistrySection 1: Chemistry

Unit 1 – MatterUnit 1 – MatterWhat is matter?What is matter?

Matter is anything that has mass and takes up is anything that has mass and takes up space.space.

Can matter change?Can matter change?Yes – e.g. snow melting, water boilingYes – e.g. snow melting, water boiling

Properties of MatterProperties of MatterWhat do we mean by the properties of an What do we mean by the properties of an

object? object?

A property is simply a characteristic that we can use to describe something.

There are physical properties and chemical properties.

1.2 Physical Properties of 1.2 Physical Properties of MatterMatter

AA physical property does not involve a substance becoming a new substance.

There are many types of physical properties that you may want to describe

Colour - red, green, blue, …?- red, green, blue, …?Texture – smooth, fine, coarse, …?Texture – smooth, fine, coarse, …?Taste – sour, salty, sweet, …?Taste – sour, salty, sweet, …?

1.2 Other Physical Properties of 1.2 Other Physical Properties of MatterMatter

States of matter at room temperature at room temperature Solid, liquid, plasma, or gasSolid, liquid, plasma, or gas

Hardness is the measure of the resistance of a is the measure of the resistance of a solid to be scratched or dented.solid to be scratched or dented.

Malleable is the opposite of brittle. Glass and is the opposite of brittle. Glass and dried clay are examples of things that are brittle. dried clay are examples of things that are brittle. Aluminum foil is malleable. Gold is malleable Aluminum foil is malleable. Gold is malleable since it can be hammered into thin sheets.since it can be hammered into thin sheets.

Copper isCopper is ductile since it can be pulled into wires.since it can be pulled into wires.

Melting and boiling points.. What is the boiling point of water? The melting point of ice?What is the boiling point of water? The melting point of ice?

Crystal form. Example, salt.. Example, salt.

Solubility is the ability of a substance to dissolve in a is the ability of a substance to dissolve in a solvent such as water. Salt is soluble while pepper is solvent such as water. Salt is soluble while pepper is not.not.

Density - mass per unit volume - mass per unit volume

1.2 Chemical Properties of Matter1.2 Chemical Properties of Matter A A chemical property describes the behaviour of a describes the behaviour of a

substance as it becomes a new substance.substance as it becomes a new substance.

Combustibility - If a substance is combustible or If a substance is combustible or flammable, it will burn when exposed to a flame. A flammable, it will burn when exposed to a flame. A substance that will not burn is described as substance that will not burn is described as nonflammable.nonflammable.

List some materials that are combustible.List some materials that are combustible.

List some materials that are nonflammable.List some materials that are nonflammable.

CombustionCombustionDuring combustion, a substance reacts During combustion, a substance reacts

rapidly with oxygen and releases energy.rapidly with oxygen and releases energy.

The energy may be in the form of heat and The energy may be in the form of heat and lightlight

Many substances can act as fuels. E.g. Many substances can act as fuels. E.g. wood, diesel oil, and kerosene.wood, diesel oil, and kerosene.

Combustion: The Fire TriangleCombustion: The Fire TriangleThe fire triangle is a convenient way to The fire triangle is a convenient way to

remember the three components of any remember the three components of any combustion reaction.combustion reaction.

Removing any one of these makes the Removing any one of these makes the triangle incomplete and puts out the fire.triangle incomplete and puts out the fire.

Reaction with acidReaction with acid Reaction with acid. The ability of a Reaction with acid. The ability of a

substance to react with acid is a chemical substance to react with acid is a chemical property.property.

Name some substances that react with acids such as Name some substances that react with acids such as vinegar.vinegar.

Would you drink acid?Would you drink acid?

Look at the side of a Coke can.Look at the side of a Coke can.

CorrosionCorrosionCorrosion is the slow chemical change is the slow chemical change

that occurs when a metal reacts with that occurs when a metal reacts with oxygen from the air. This chemical reaction oxygen from the air. This chemical reaction forms a new substance called an oxide.forms a new substance called an oxide.

Different kinds of corrosion:Different kinds of corrosion:RustingRustingAluminum corrosionAluminum corrosionSilver tarnishSilver tarnish

RustingRustingRusting is a chemical change that is a chemical change that

involves iron, oxygen from the air, water, involves iron, oxygen from the air, water, and salt or other minerals that may be and salt or other minerals that may be dissolved in water.dissolved in water.

Where do we normally see rust?Where do we normally see rust?

What can we do to prevent rust?What can we do to prevent rust?

Aluminum CorrosionAluminum CorrosionAluminum has a chemical property similar Aluminum has a chemical property similar

to iron in that it reacts with oxygen to form to iron in that it reacts with oxygen to form an oxide.an oxide.

The The aluminum oxide that forms is strong that forms is strong and it is unaffected by water.and it is unaffected by water.

Silver tarnishSilver tarnish Unlike iron and aluminum, silver does not react with Unlike iron and aluminum, silver does not react with

oxygen but it does react with sulphur.oxygen but it does react with sulphur.

Sulphur is found in Sulphur is found in MustardMustard EggsEggs Acid rainAcid rain

Silver sulphide causes silver to develop a black coating.Silver sulphide causes silver to develop a black coating.

The black layer is annoying but it can be removed by The black layer is annoying but it can be removed by polishing the silver.polishing the silver.

Preventing CorrosionPreventing CorrosionThere are many ways to prevent There are many ways to prevent

corrosion:corrosion:Painting metal prevents oxygen from getting at the Painting metal prevents oxygen from getting at the

metalmetalUse plastic instead of steelUse plastic instead of steelCathodic protection – using one metal to attract – using one metal to attract

corrosion (oxygen) from another.corrosion (oxygen) from another.

DensityDensityA quantitative physical property of matterA quantitative physical property of matter

Which is heavier: a 12 inch bar of gold or a Which is heavier: a 12 inch bar of gold or a pillow full of feathers?pillow full of feathers?

A 12 inch bar of gold weighs more than a A 12 inch bar of gold weighs more than a pillow full of feathers even though the pillow full of feathers even though the pillow takes up more space? Why?pillow takes up more space? Why?

Gold is more dense. It has more matter Gold is more dense. It has more matter per unit volume.per unit volume.

Density is the amount of matter per unit is the amount of matter per unit volume of that matter.volume of that matter.

Density (D) = Mass (m) / Volume (V )

If you know any two of the three variables If you know any two of the three variables (D, m, V), you can solve for the third.(D, m, V), you can solve for the third.

m = DV V = m / D

Sample density question #1Sample density question #1 If a rock has a mass of 49 g and occupies If a rock has a mass of 49 g and occupies

a volume of 7 cma volume of 7 cm33, what is the density?, what is the density?

D = m / VD = m / V = 49 g / 7 cm= 49 g / 7 cm33

= 7.0 g/ cm= 7.0 g/ cm33

Solve these sample density Solve these sample density questionsquestions

1. An object has a mass of 250 g and occupies a volume of 1. An object has a mass of 250 g and occupies a volume of 14.5 cm14.5 cm33, what is the density?, what is the density?

2. A piece of wood occupies a volume of 46 cm2. A piece of wood occupies a volume of 46 cm33 and it has a and it has a mass of 100 g. What is the density of the wood?mass of 100 g. What is the density of the wood?

3. An unknown metal has a density of 2.6g/cm3. An unknown metal has a density of 2.6g/cm3 3 and a mass of and a mass of 15 g. How much volume does this piece of meal occupy.15 g. How much volume does this piece of meal occupy.

4. A sample of a particular liquid has a density of 6.85 kg/L 4. A sample of a particular liquid has a density of 6.85 kg/L and it occupies a volume of 3.4 L. How much does this and it occupies a volume of 3.4 L. How much does this particular sample weigh?particular sample weigh?

Answer to question #1Answer to question #1D = m/VD = m/V

D = 250 g/14.5 cmD = 250 g/14.5 cm33

D = 17.24 g/cmD = 17.24 g/cm33

Answer to question #2Answer to question #2D = m/VD = m/V

D = 100g / 46 cmD = 100g / 46 cm33

D = 2.17g/cmD = 2.17g/cm33

Answer to question #3Answer to question #3D = m/VD = m/V

V = m/DV = m/DV = 15g / 2.6 g/cmV = 15g / 2.6 g/cm33

V = 5.77 cmV = 5.77 cm33

Answer to question #4Answer to question #4D = m/VD = m/V

M = DVM = DVM = 6.85 kg/L x 3.4 LM = 6.85 kg/L x 3.4 LM = 23.29 kgM = 23.29 kg

** Note that volume can be expressed as ** Note that volume can be expressed as cmcm33, m, m33, ml, or even L., ml, or even L.

Approximate Densities of Some Approximate Densities of Some Common MaterialsCommon Materials

SubstanceSubstance DensityDensityKg/mKg/m33 g/cmg/cm33

GoldGold 19 30019 300 19.319.3

SilverSilver 10 50010 500 10.510.5

AluminumAluminum 2 7002 700 2.72.7

IceIce 920920 .92.92

Wood (birch)Wood (birch) 660660 .66.66

Distilled WaterDistilled Water 1 0001 000 1.01.0

Water is denser than ice!Water is denser than ice!Why is this so important?Why is this so important?

It means that ice floats in water instead of sinking. It means that ice floats in water instead of sinking. Think of the poor fish if this was not the case.Think of the poor fish if this was not the case.

Why is ice less dense than water?Why is ice less dense than water?When water freezes, it expands which means that When water freezes, it expands which means that

the same mass of water is spread over a greater the same mass of water is spread over a greater volume.volume.

HomeworkHomeworkAnswer questions 2, 3, 4 on page 25 of Answer questions 2, 3, 4 on page 25 of

the text.the text.

WHMISWHMISWHMIS (Workplace Hazardous Material WHMIS (Workplace Hazardous Material

Information System)Information System)

These symbols are found on products to These symbols are found on products to indicate exactly why and to what degree a indicate exactly why and to what degree a product is dangerousproduct is dangerous

Assignment #1Assignment #1Create a simple map of your home and Create a simple map of your home and

indicate where you would have found indicate where you would have found products with some of the hazardous products with some of the hazardous household product symbols that we have household product symbols that we have discussed.discussed.

1.7 Physical and Chemical 1.7 Physical and Chemical ChangesChanges

A burning candle – what happens?A burning candle – what happens?

As the candle burns, the wax melts (a solid As the candle burns, the wax melts (a solid becomes a liquid), and then it hardens (a becomes a liquid), and then it hardens (a liquid becomes a solid). These are physical liquid becomes a solid). These are physical changes.changes.

The wax also combusts producing heat and The wax also combusts producing heat and light. This chemical change involves the wax light. This chemical change involves the wax becoming carbon dioxide, water, and energy.becoming carbon dioxide, water, and energy.

What is a physical change?What is a physical change? In a In a physical change, the substance involved , the substance involved

remains the same substance, even though it may remains the same substance, even though it may change state or form. When candle wax melts, it is change state or form. When candle wax melts, it is still wax.still wax.

Changes of state – melting, boiling, freezing, Changes of state – melting, boiling, freezing, condensing, and dissolving – are physical condensing, and dissolving – are physical changes.changes.

Most physical changes are easy to reverse.Most physical changes are easy to reverse.

What is a chemical change?What is a chemical change? In a chemical change, the original substance is changed into In a chemical change, the original substance is changed into

one or more different substances that have different one or more different substances that have different properties.properties.

As candle wax melts, some of the wax particles combine with As candle wax melts, some of the wax particles combine with oxygen to produce water vapour, carbon dioxide, heat, and oxygen to produce water vapour, carbon dioxide, heat, and light, but it is still wax. light, but it is still wax.

A chemical change always involves the production of new A chemical change always involves the production of new substances. Examples include burning, cooking, and rusting.substances. Examples include burning, cooking, and rusting.

Most chemical changes are difficult to reverse.Most chemical changes are difficult to reverse.

Clues That a Chemical Change Clues That a Chemical Change Has HappenedHas Happened

A new colour appears.A new colour appears.

Heat or light is given off.Heat or light is given off.

Bubbles of gas are formed.Bubbles of gas are formed.

A solid material forms in a liquid. (A solid material forms in a liquid. (Precipitate)Precipitate)

The change is difficult to reverse.The change is difficult to reverse.

HomeworkHomeworkAnswer questions 2 and 3 on page 30.Answer questions 2 and 3 on page 30.