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DISCLAIMER

This document consist of scanned copies of the BGCSE and/or BJC past papers produced by the Bahamas

Ministry of Education. The Student Shed accepts no responsibility or liability for the contents within this

document, including but not limited to; answers that may be highlighted, missing papers or missing

questions.

It is the sole responsibility of the user to determine the correct and most suitable answers for each

question contained therein.

30s1/1 BGCSESchool Number Candidate Number

Surname and Initials

CHEMISTRYPAPER 1 305I./1

wednesday 18 MAY 2016 t2:00NooN-t:r5p.M.

Additional materials:None

MmrsrRYNarroNAL

OT EnUCATIoNExarvuNATroNS

BAHAMAS GENERAL CERTIFICATE OF SECONDARY EDUCATION

INSTRUCTIONS AND INFORMATION TO CANDIDATES

Do not open this booklet until you are told to do so.

Write your school number, candidate number, surname and initials in the spaces provided above.

Answer ALL the questions on this paper.

For each question in this paper, four suggested answers A, B, C and D are given.

Circle the letter of the response which you consider to be correct.

Attempt ALL the questions. Marks will NOT be deducted for wrong answers. Your total scoreon this test will be the number of correct answers given.

Relative atomic masses are given in the Periodic Table of elements provided on page 2.

The volume of one mole of gas at room temperature and pressure (r.t.p.) is.24000cm3 and atstandard temperature and pressure (s.t.p.) is22400cm3.

For Examiner's Use

TOTAL MARKS

= This question paper consists of 14 printed pages and 2 blank pages.

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-3-

l. What is the name of a group of chemicals that speed up a chemical reaction?

A catalystsB galvanizersC oxidising agentsD reducing agents

2. The diagram represents a scale found on a centimetre rule.

What is the value indicated bv the arrow?

0.41 cm0.42 cm4.10 cm4.20 cm

3. The reading on a thermometer indicates the temperature of a boiling liquid is l0loC.

Which liquid could the thermometer have been placed in?

liquid purity

A ethanol pure

B methane pure

C propane lmpure

D water impure

4. A sample of water is heated from - lOoc to l lOoc in a l5 minute period. .

How many single states of matter and how many mixed states of matter will the water undergo?

single states mixed states

A 2 5

B 2 .,

C 3 2

D J 0

ABC

D

0cm I 2 aJ 4 6 7 8 9 10 11

4-

5. How is the number of neutrons determined for any atom?

A adding the number of protons to the mass number

B doubling the atomic number

C equals the number of electrons

D subtracting the number of protons from the mass number

6. Where on the Periodic Table would the element with the electronic conflguration 2, 8, 3 be found?

A Group IIB Group VIIVOC Period 3

D Second Period and Group III

7. In the Bohr model of an atom, how many orbits are needed to hold silicon's 14 electrons?

AIB2C3D4

8. Carbon dioxide molecules with slightly different masses have been found.

Which factor accounts for this mass variation?

A allotropesB isomers

C isotopes

D states of matter

9. What is the total number of electrons found in a water molecule?

A2B8c10D18

-5-

The list below contains the names of the four different types of chemical bonds. Use this information toa[swer questions 10 to 12. The choices may be used once, more than once or not at all.

covalent

dativeionicmetallio

Which type of bond is formed when

t2.

ABCD

D

D

C

C

A.

A.ll.

ABC

D

7

48

98

BCD

hydrogen and oxygen bond to form water;

the lattice structure ofNaC/ is formed;

ammonia bonds with a fourth hydrogento fbrm the ammonium ion?

13. What is the amount in moles, of NaOH, found in32 gofNaOH?

0.80 moles1.25 moles40 molesI 280 moles

What is the relative molecular mass of HrSOo?

A3

15. Which element can be found in the form of a diamond?

10.

carbonkryptonpotassiumsilver

DCBA

14.

ABCD

aofl^^

16. What

ABC

D

-6-

is the molecular formula of a compound with the structural formula CH3CH2CH3?

CH3C8H

crH*(cH3)2cH2

How many moles of oxygen gas are needed to balance the combustion reaction of one mole ofbutane?

CrH,n + XOz+ 4CO2 + 5H2O

%

5

6%

9

What is the molecular formula of a hydrocarbon with an empirical formula of CH. and an M, of30?

A CH,B CrHu

c crH,D CoH,n

Hydrogen bromide gas dissolves in a liquid and ionises to produce hydrogen ions as the only

positive ions in a liquid.

Which liquid causes hydrogen bromide gas to ionise?

t7.

ABC

D

18.

19.

ABC

D

acetone

methylbenzenetoluenewater

Which statement about an acid is true?

A forms water with an alkaliB pHis>7C forms negatively charged hydronium ions in water

D is a non-electrolyte

20.

-7-

21. When coppff reacts with hot concentrated sulfuric acid it produces copper sulfate.

Which other products are formed?

A hydrogen gas onlyB water onlyC water and sulfur dioxide gas

D water and hydrogen gas

22. Which salt remains when a solution of HrSOo is titrated with a solution of Ca(OH)r?

A calcium hydroxideB calcium oxideC calcium sulfateD calcium sulfite

23. The table shows the colours that Universal Indicator becomes when added to four differentsolutions.

Which row in the table correctly matches the colour of the indicator and the solution?

name of solution colour of Universal Indicator

A nitric acid blue

B potassium nitrate green

C sodium hydroxide yellow

D ammonia solution red

24. which ion is indicated by a blue-green colour in a firework display?

A Cu2*B Ba2*

C Na+D Ca2*

-8-

Use the list of gases to answer questions 25,26 and 27 . The choices can be used once, more than once ornot at all.

A ammoniaB hydrogen chlorideC sulfur dioxideD chlorine

Which gas

25. turns moist red litmus blue; ABCD

26. forms dense white fumes with ammonia gas; A B C D

27. turns moist blue litmus red and then bleaches it? A B C D

28. What is the name of the process by which electricity is used to bring about a chemical change?

A corrosionB electrolysisC oxidationD voltage

29. Which change occurs to the ion at the anode during electrolysis?

A reductionB oxidationC gains electronsD gains mass

30. This reaction is part of the contact process.

2SO2 + 02+2SO3

What happens if the amount of SO, is increased?

A O, increases and SO, increases

B O, decreases and SO, decreases

C O, increases and SO, decreases

D O, decreases and SO, increases

-9-

31. What is a change in concentration of either a reactant or product over a period of time called?

reaction ratereactant concentrationproduct concentrationstate change

Zine is less reactive than magnesium.

what is the reactivity relationship between zinc and magnesium?

A Magnesium can displace zlrnc ions from zinc compounds.B zinc candisplace magnesium from magnesium compounds.C Magnesium is lower than zinc in the reactivity series.D Zinc is a stronger reducing agent than magnesium.

Which of these statements does not describe what happens during a redox oxidation?

A a decrease in oxidation numberB a loss of protonsC a gain of oxygenD a loss of hydrogen by a covalent molecule

ABC

D

32.

JJ.

<oa1 a^

-10-

Use the table to answer questions 34 and 35.

The tabrle shows the produets formed at the anode and the eathode during eleetolysis.

Which row in the table shows an

34. incorrect product at orte of the eleotrodes;

electrolysed compound which did not produce hydroxide ions? A

Magnesium metal is made by the electrolysis of molten MgClr. One ofthe half-reactions is shown.

IvIg2* * 2e- -+Mg

S/hich statement about the eleotrolysis of molten MgClris correct?

A magnesium is made at the cathode.

B magnesium ions are oxidised.

C chloride ions are reduced at the anode.

D chloride ions gain electrons during the process.

37. Which pollution problem can he caused by the ammonia, NH, produced by bumrng fossil fuels?

A acid raiuB eutrophicationC global warfitingD depletion of the ozone layer

35.

D

D

compound electrolyted product atcarbon anode

product at carboncathode

A rrolten lead bromide bromine lead

B potassium nitrate solution oxygen hydrrgen

C consenfrated sodium chloride solution oxygen hydrogen

D copper sulfats solution oxygen oopper

HHlt38.

-11-

The diagram shows the structural fomrula of ethane.

H_ C_c _HIIHH

The electronic configuration of C isZ,4 and H is l.

How many covalently bonded electrons surround each carbon atom in the above structure?

What is the correct order of the following hydrocarbons in terms of increasing boiling points?

propane CrH, methane CHo and ethane CrEtu

methane, propane, ethaneethane, methane, propanemethane, ethane, propaneethane, propane, methane

Which name is given to a series of compounds that differ fiom each other by a fixed repeating unit?

A heterogeneous seriesB homologous seriesC homogeneous seriesD hydrocarbon series

A2B4C6D8

39.

ABCD

40.

47, Dilute a.cetic acid, eommonly known as vinqgar" is the second smallest carboxylie aeid,

W'hieh choice correctly matches the correct formula and name for this aeid?

acld name formula

A ethanoic cH3c,ooH

B hydrochloric HC'

C methanoic CHOOH

D methanoie cHo2H

42. Which pair shows two elomenls which are liquids at toom temperature and pressure?

brornine and mercuryohlor.ine andwaterfluorino arid silveroxyge-n and zinc

\Mhich element in the Periodis Thble has an allotrope that is capable of conducting

electricity?

carb0nchlorineoxygensulfir

ABCD

43.

AB.

CD

_13_

Questions 44 and 45 are about the refining of petroleum.

44. which method is used to obtain lubricating oil from crude oil?

A centrifugationB chromatographyC filhationD fractional distillation

45' Lubricating oils undergoes additional processing to obtain larger amounts of the more valuablehydrocarbons.

What is the name of this process?

A uackingB esterifieationC hydrolysisD polymerisation

46. Which compound is an unsaturated hydrocarbon?

A ethaneB etheneC ethanoic acidD ethyl methanoate

47. Blanco Bleach is a Bahamian company.

Which element is needed in large quantities by Blanco to make bleach?

A bromineB chlorineC fluorineD iodine

troa1-r^

-14-

48. Carbon dioxide emissions have steadily increased since the start of the industrial age. As a result,

the carbon dioxide in the Earth's air has increased by approximately 20Yo.

What are the effects of this change?

A acid rainB global warmingC both of the above

D none of the above

49. Which ore is aluminum metal extracted from?

A aragoniteB bauxiteC galena

D haematite

50. Iron is extracted from its ore using a blast furnace.

Which form of iron is extracted from the blast furnace?

A impure pig ironB pure liquid ironC solid iron nuggets

D stainless steel iron

305u2

CHEMISTRYPAPER 2 3O5II2

Wednesday 18 MAY 2016 1:30P.M.-3:00 P.M.

Additional materials:None

MrxrsrRYNauoNAL

OT EOUCATIONExavuNATroNS

BAHAMAS GENERAL CERTIFICATE OF SECONDARY EDUCATION

INSTRUCTIONS AND INFORMATION TO CANDIDATES

Do not open this booklet until you are told to do so.

Write your school number, candidate number, surname and initials in the spaces provided above.

Answer ALL the questions on this paper.

Read each question carefully and make sure you know what you have been asked to do beforestarting your answer.

The instruction NAME . . . requires an answer in words NOTchemical symbols.

Show ALL your working when answering numerical questions.Lines are provided on the question paper for your answers.You should write your answers on these lines only.

A copy of the Periodic Table is provided on page 2.

The mark for each part question is given in brackets [ ].

BGCSECandidate NumberSchool Number

Surname and Initials

l:I

II

!-

:-_--:

FOR EXAMINER'SUSE

I

2

J

4

5

6

7

8

TOTAL

This question paper consists of 16 printed pages and 4 blank pages.

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-3-

l. This question is about the Periodic Table.

(a) What is the Periodic Table?

lll(b) State how the Modern Periodic Thble is arranged.

Ill(c) Name the least reactive group of elements in the Periodic Table.

tll(d) Name the series of elements to which Mn belongs.

tll

(e) Name the element that is in Period 3 Group II.

(f) Name the element that has cation X3* and electronic configuration 2,8.

(g) State the name of the element with the symbol Sb.

t1l

tll

t1l

(h) State the charge on one ion of sodium.

t1l

(i) Name the grey/purple solid halogen.

t1l

ttl

(j) Name a non-metal that occupiesTS%o of the air.

TOTAL MARKS [10]

The diagram shows an electrolytic cell.

(a) Use the letters

carbon.

above to identify the part(s) of the cell that may be made of

(ii) Name the allotrope of carbon used to make the parts mentioned in (a)(i).

In an electrolysis cell, name the place where oxidation and reduction reactionsoccur.

oxidation

reduction

(b) Describe in terms of electrons, the meaning of redox reactions.

t1l

t1l

(iii)

tzl

t2l

-5-

(c) Aluminium can be extracted by electrolysis from its ore, Bauxite. During the electrolysisoxygen is produced. The anode reacts with this oxygen, as shown in the equation.

C + O, -->

CO,

State the oxidation number of each carbon in the following.(i)

(ii)

(iii)

C

CO,

State which element is oxidised and which is reduced in the equation.

oxidised

reduced

t1l

tll

State why aluminium cannot be extracted from its ore by reduction with carbon.

tll

(d) Iron is extracted from its ore by a reaction with carbon.

State the rurme of the ore.

tll

TOTAL MARKS [10]

aJ.

-6-

(a) Litmus turns red in acid and blue in alkali.

Write the formulae of the ions in an acid and an alkali that cause litmus to have these

colours.

acid alkali

(b) The diagrams show the method of preparing a solid sample of a soluble salt, copper(Il),

using a base, copper(Il) oxide, and an acid, hydrochloric acid.

l2l

warmed mixture ofexcess copper(Il)

oxide(s) and

hydrochloric acid(I)mixture of excess

copper(Il) oxide

and hydrochloricacid

filter paper toremove excess

insolublecopper(Il) oxide

filter funnel

aqueous copper(Il)solution ready for

evaporation

stage I stage2

(i)

(ii)

Explain why excess copper(Il) oxide is added to hydrochloric acid in stage

State the pH of the copper(Il) chloride solution in stage 2.

(iiD After stage 2,the copper(Il) chloride solution is heated.

Explain the reason for heating the copper(Il) chloride solution.

Balance the chemical equation for the reaction between CuO and HCI(aq).

_ CuO(s) + _ HCI(aq) -------- CuCl,(ad + _ HrO(I)

1.

t1l

tll

t1l

(iv)

t1l

-7-

(c) Coal, crude oil and natural gas contain small amounts of sulfur, which produces acolourless, toxic gas when burned in oxygen gas. The gas dissolves in rainwater andproduces acid rain.

The chemical equation for this reaction is shown.

SOr(S) + HrO(D -+ HrSOr(aO)

(i) Write a word equation for this chemical equation.

(ii) Calculate the relative molecular mass of the product.

tu

(iii) Determine the amount, in moles, in 4l grams of HrSO,

tll(iv) One way of reducing acid rain is to generate electricity without using fossil

fuels. Instead, we can use renewable energy sources.

Name ONE renewable energy source.

t1l

TOTAL MARKS [101

t1l

Scientists have discovered many subatomic particles. The three most

the proton, neutron and electron.

(a) (i) Fill in the blanks to complete the table for these three named particles.

particle mass (amu) charge

proton

neutron

electron

(ii) State why an atom is eleetrically neutral'

for chemistry are

The table gives values for the subatomic particles in atoms. Complete the table,

using the Periodic Table onPage2.

symbol number ofprotons

number ofneutrons

number ofelectrons

I 0 I

Na t2 l1

Fe 26 26

P3- 15 31

tll

t3l

tll

(iii)

(iv) Write the electronic configuration for Na.

(b) Carbon-l2, carbon-l3 and carbon-14 xe all isotopes of the solid carbon.

State how these isotopes are different and similar'

different

t4l

tll

similar

TOTAL MARKS [101

-9-

5. The industrial preparation of ammonia involves combining nitrogen and hydrogen at a hightemperature and very high pressure in the presence of a catalyst.

(a) Name the process by which ammonia is manufactured.

(b) Name the catalyst used in the process.

t1l

tll

(c) The overall chemical equation for the reaction is shown.

Nr(g)+:Hr(s)=zNH,(e)

Calculate the amount, in moles, of hydrogen required to react with nitrogen to produce 13

moles of ammonia, using the equation.

(d) Explain why only partial conversion occurs in the manufacture of ammonia.

(e) State what happens to the unreacted nitrogen and hydrogen gases.

(f) A mixture of hydrogen, nitrogen and ammonia has a total volume of 48 dm3 at roomtemperature and pressure. The ammonia makes up 45o/o of this mixture.

What is the amount, in moles, of ammonia in the mixture?

t1l

t1l

tll

l2l

(g) Give the chemical name for a fertiliser, made by reacting ammonia with sulfuric acid.

t1l

tJe{ngol*melemonsom!5U.dtnnv,tbeeowlentbondingdiagramofer lmule,ofmont$Nt.L.

TOTALMARKS [101

-11-

6. The table shows data collected and recorded from various metals reacting with aqueoushydrochloric acid.

metal maximum temperature recorded (oC)

aluminium 85

copper 2t

ron 35

lead 23

magnesium 95

zJnc 55

(a) (i) Arrange the metals fi'om the least to the most reactive.

tll(ii) Write a word equation for magnesium reacting with aqueous hydrochloric acid.

I' J -l

12)

(iil) state the test and positive results for the gas produced in (ii).

test

least reactive

Imost reactive

positive results t2t

-

-12-

(b) Use your knowledge of the reactivity series and metals to explain the following

observations.

(D Initially aluminium did not react with the hydrochloric acid but after a time itreacted vigorously.

(iD Copper pots do not react with lemon juice but aluminium and iron pots do.

(iiD A student wanted to put a piece of potassium metal into the hydrochloric acid

solution.

Explain why the teacher did not allow the student to do this.

(c) Metals are economically important.

Explain the following observations based on the economic importance of metals.

(i) Manufacturers of pots use aluminium or steel instead of copper to make the vast

majority of pots.

(iD There are finite amounts of metals.

State a method that can be used to preserve these metals for future generations.

t1l

TOTAL MARIG [10]

tll

tll

tll

lll

-13-

7. The pie chart shows the various hydrocarbons that are found in natural gas.

Per cent (7o)

nitrogen and otherhydrocarbons

4%

propane butane4%

ethane

t0%

(i) Give the name of the homologues series the hydrocarbons in the pie chart belong to andits general formula.

homologues series

general formula

(ii) Calculate the relative molecular mass of butane.

(iii) Draw the structural formula of butane.

t2l

t1l

t2l

<oz1a.,

(iv) write the word equation for the complete combustion of butane.

t2)

-14-

(v) Arrange the named hydrocarbons butane, ethane, methane and propane from the highest

to the lowest boiling Points.

highest boiling point

lowest boiling point

(vi) State ONE environmental problem burning natural gas can cause.

tll

lll

(vii) State ONE industrial use of natural gas.

t1l

TOTAL MARKS [101

-15-

8. The cooling curve shows the relationship between temperature and time for a pure substance asit cools. The identity of the pure substance can be determined from the data shown by the graph.Sections of the graph are labelled with the letters A, B, C, D and E.

temperature/oC

t40

r20

100

80

50

40

20

0

-20

40

(a) (i) Give the name of the pure substance that produced this cooling curve.

(ii) How many states of matter are shown by the cooling curve?

(b) Give the name of the process when the pure substance changes from:

(i) A to B;

(ii) EtoD.

t1l

(c) State how the addition of salt affects the numerical value of thepoint.

substance's boiling

tll

t1l

tll

time/min

<Q Al l'2

t1l

(d)

-16-

Name the bonding that holds the atoms to each other in the molecules.

(e) Draw the particle packing for the appearance of the pure substance at section E of the

graph.

(f) Briefly explain how the particle packing changes as it goes from E to C.

Solid white crystals of ammonium chloride turn into a colourless gas when they are

heated. The white crystals reappear when the gas is cooled.

(i) Name the change from solid to gas.

(iD Give the common name for solid CO, that can undergo this same change.

TOTAL MARKS [101

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(e)

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30s1/3 BGCSESchool Number Candidate Number

Surname and Initials

I

I

rI

--I

--

PAPER 3 3051/3

Equations and diagrams should be given whereverthey are helpful. Essential working must be shown.

The intended marks for each question or part questionare given in brackets [ ].

Relative atomic masses are given in the PeriodicTable printed onpage 2.

ADDITIONAL INFORMATION

s.t.p. (t : 0oc, p : 760mmHg)

The volume of one mole of gas atroomtemperatureand pressure (r.t.p.) is 24 000 cm3.

For Examiner's IJse

Section A

1

2

aJ

4

Section B

5

6

lTOTAL

CHEMISTRY

Monday 30 MAY 2016 12:00noon-t:30p.M.

Additional materials:Graph paper

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BAHAMAS GENERAL CERTIFICATE OF SECONDARY EDUCATION

INSTRUCTIONS AND INFORMATION TO CANDIDATES

Do not open this booklet until you are told to do so.

Write your school number, candidate numbeq sufllame and initials at the top of this page as wellas at the top of all lined paper submitted.

Answer ALL the questions in Section A in the spaces provided on this question booklet andany TWO questions from Section B on the lined paper provided at the back of this questionbooklet.

= This question paper consists of 14 printed pages, 4 lined pages and. 2 blank pages.

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-3-

BLAI{K PAGE

SCIENCE GRAPH PAPER

MINISTRY OF EDUCATIONBAHAMAS GENERAL CERTIFICATE OF SECONDARY EDUCATIONEXAMINATION

AB7

School No. Candidate No. Level: For Examiner'sUseSubject Number & Title: Paper:

Surname & Initials: Section:

Signature: Date: Qu. No.

-4-

Section A

1. A titration experiment was performed by adding 23.5 cm3 of hydrochloric acid from a burette toneutralise 20 cm3 potassium hydroxide solution in a conical flask. The concentration of the acidwas 0.03 mol/dm3.

(a) Explain why a burette, rather than a measuring cylinder was used in the titration.

(b) Phenolphthalein was the indicator used in the experiment.

State the colour of the indicator at the endpoint of the titration.

til

(c) (i) Write a chemically balanced equation for the neutralisation reaction betweenhydrochloric acid and potassium hydroxide.

(ii) Calculate the amount, in moles, of hydrochloric acid that completely neutralisedthe potassium hydroxide in the titration.

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(iii) Calculate the concentration of potassium hydroxide, using your answers to (c)(i)and (ii).

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(d) Hydrochloric acid is a strong acid which ionises completely in solution.

Write an ionic equation to show that a solution of hydrochloric acid is a strong acid thationises completely in solution. Include state symbols in your equation.

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(e) State the range of values on the pH scale that indicate acids.

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-5-

2. The diagram shows a schematic sketch of an electrolysis cell.

impure copper

unknown

(a) Explain the term electrolysis.

electrolyte

cathode

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(b) The electrolyte in the purification of copper is copper(Il) sulfate.

(i) State the materials that the anode and cathode are each made of.

anode

cathode

(ii) State the half-equation at the anode and at the cathode in the purificationcopper.

anode reaction

cathode reaction

(iii) Describe what happens to the colour of the electrolyte as the reaction proceeds.

121

of

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(")

Modern aluminium fryirrg pans are anodised.

Name the substance which is used to cover and protect aluminium.

Name the type of substance found in the unknown.

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aJ.

*7-

Two important metals are aluminium and iron.

(a) Complete the table.

(b)

(d)

(i) Calculate the mass of hematite needed to produce 168 g of iron metal, usingequation.

FerOr(s) + 3CO(g) ----->

2Fe(1) + 3CO2(g)

(ii) State the oxidation states of iron in each of the substances.

FerOr(s)

Fe(1) l2l

Write the ionic half-equation for the reaction at the cathode in the extraction of aluminiumby electrolysis.

Iron and aluminium form many alloys.

(i) Define the term alloy.

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State oNE advantage of using an alloy of aluminium compared to aluminiummetal.

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(c)

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metal ore extraction process

aluminium name:

formula:

electrolysis

1ron name: hematite

formula: FerO,

(ii)

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r

4.

-8-

Manufacture of sulfuric acid is of great economic importance.

A schematic diagram for the manufacfure of sulfuric acid is shown.

or--E o2 H2SO4

-l product product Y Product Z

-,liquid S catalyst

(a) (i) write chemically balanced equation for the formation of product X in part A.

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(ii) Name the catalyst used in part B.

(iii) Explain why product Y is dissolved in concentrated sulfuric acid in part C,ratherthan water.

The formation of product Y in part B is a reversible reaction.

2SOrfr) f Or(*) ==

2SO3G) AH: -I97 kJ/mol

Explain the effect of the actions on the equilibrium yield of sulfir rioxide, according toLe Chatelier's Principle.

(D adding more oxygen is added

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(ii) decreasing the pressure

12)

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(ii| There was a leakage of sulfur trioxide from part B and 120 g of sulfur trioxideescaped.

Determine the volume this mass of sulfur trioxide gas would occupy measuredat room temperature and pressure.

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TOTALMARKS [10]

I

5.

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SECTION B

Use the information in the chart to answer the questions.

solution A

-:-__*

yellow precipitate B + ['"1-i"" --]ll

--t \evaporation add iron(Il) sulfate and

and drying concentrated HC/lritturns lilac brown ringin a flame between layers

Iadd KI solution

contains a metalremoved from paint

(a) (D

(ii)

Identify solution A, yellow precipitate B and solution C. t3l

Write the complete balanced equation for the reaction between solutions A andKI. l2l

(b) -:

-1 1-

Two tests were performed on unknown substance D. Use the information in the chart toanswer the questions.

add HC/ andbarium chloride

ItAlkaline gas E

white precipitate F

turns moistred litmus blue

IiaddHCl

It

Determine which of the two fertilisers has the higher percentage of nitrogen.

State the role of nitrogen in plants.

add NaOHand warm

It

white solid Gthat sublimes

(i) Identifz substance D, gas E, white precipitate F and the white solid G. L4l

(ii) Write a complete balanced equation for the reaction between phosphoric acidand gas E. pl

(c) Fertilisers are important chemical compounds. However the sale of large quantities of. fertilisers containing nitrates is prohibited.

(i) Explain why fertilisers, like ammonium nitrate, are closely monitored. [1]

(ii) Two fertilisers that contain nitrogen are alnmonium sulfate and ammoniumphosphate.

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(iv) Determine the mass of nitrogen in 10 g of the best fertiliser, based on your answerto (c)(ii).

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(d) (D

(i')

-12-

Name one ion that causes eutrophication.

Describe the process of eutrophication.

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TOTAL MARKS [201

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6' The diagram shows a series of organic reactions that change ethene into other organic compounds.

polyethene ethyl ethanoate

lri t'iethene

t\,'

.---1/. ethanolt\

3)-----]' ,/ethanoic acid

t-t_.151

t\6)

-__-_1 ,,.ethane chloromethane

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carbon dioxide * water

(a) (i)

(iD

(iii)

State the type of chemical reactions that occur inindicated by the alrows.

each of the stages, I to 7,

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36.4% oxygen and an unknownthe compound. The molecular

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TOTAL MARKS [201

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write balanced chemical equations for reaction 5 and for reaction 6.

The diagram shows a compound.

HH

Copy and draw TWO successive links in the polymer chain with this compound.

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121

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C:CHH

(b)

(iv) State the name of the monomer and polymer shown.

(v) Give ONE use for the polymer in (a)(iii).

An organic compound is composed of 54.5%o carbon,percentage of hydrogen. There are no other atoms informula of the compound is 88.

Calculate its empirical and molecular formulae.

7.

-14-

An experiment was carried out to investigate the effect of acid on limestone (calcium carbonate), Aconical flask containing dilute nitric acid was placed on a balance. Lumps of caleium carbonatewere added to the dilute nitric acid and a loose cotton wool plug was quicklyplaced in the neck ofthe conical flask.

The chemical reaction between calcium carbonate and dilute nitric acid produced calcium nihate,water and carbon dioxide gas which escape into the air. The conical flask and its contents wereweighed at regular intervals and the results wers recorded in a table.

time/minutes 0 1 2 J 4 5 6 7 8 9 10 11 i-aLL

mass of flask andcontents/g

96 82.s 74 66.5 60 54 49 46 M 43 42 42 42

Plot these results on a graph. 16l

(i) Use the graph to determine the decrease in the mass in the first 30 s. t1l

(i0 Explain why there is a decrease in the mass of the flask and its contents as time

(a)

(b)

(c)

(d)

(e)

proceeds.

state the purpose ofplacing the cotton wool in the neck of the flask.

Write a balanced equation for the reaction.

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(i) Calculate the mass of carbon dioxide released into the air when all of the caloiumcarbonate was completely reacted with the dilute nitric acid in the experiment.

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(i, Calculate the volume of carbon dioxide that escaped into the air at r.t.p., usingyour answer in (e)(i). l2l

(f)

-15-

When concentrated nitric acid, HNO3, w&S spilled on a ro11 of copper wire, nitrogendioxide, NOr, Cu(NOr)r, and water were formed. Nitrogen dioxide is a reddish browntoxic gas and the building was evacuated.

Explain why the reaction of nitric acid with copper wire is more dangerous thanif the acid had fallen onto the same mass of copper bars. use particle theory tosupport your explanation. L2l

(i)

(ii)

(iii)

(iv)

Explain how the toxic gas was able to flll the lab quickly. use particle theory tosupportyourexplanation. [1]

Balanced the chemical equation for the reaction between concentrated nitric acidand copper.

HNO3 * Cur Cu(NO3)2 + H2O +

Calculate the volume of nitrogen dioxidepressure, when 320 g of copper completely

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produced at room temperature andreacts with concentrated nitric acid.

12)

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QuestionWrite o.n both sides of the paper

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QuestionWrite on both sides of the paper

QuestionWrite on both sides of the paper

t

-t9-

QuestionWrite on both sides of the paper