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University of Cambridge International Examinations International General Certificate of Secondary Education

This document is an examination paper for the International General Certificate of Secondary Education (IGCSE) Chemistry subject, specifically Paper 1 Multiple Choice from May/June 2012. It contains instructions for answering the questions, a total of 40 multiple-choice questions covering various chemistry topics, and a periodic table. The exam is designed to assess students' understanding of chemistry concepts and their ability to apply this knowledge.

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0% found this document useful (0 votes)

13 views189 pages

University of Cambridge International Examinations International General Certificate of Secondary Education

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aishaseedin

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Available Formats

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UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS

International General Certificate of Secondary Education

CHEMISTRY 0620/12
Paper 1 Multiple Choice May/June 2012

45 Minutes
Additional Materials: Multiple Choice Answer Sheet
*7216958504*

Soft clean eraser

Soft pencil (type B or HB is recommended)

READ THESE INSTRUCTIONS FIRST

Write in soft pencil.

Do not use staples, paper clips, highlighters, glue or correction fluid.
Write your name, Centre number and candidate number on the Answer Sheet in the spaces provided unless
this has been done for you.

There are forty questions on this paper. Answer all questions. For each question there are four possible
answers A, B, C and D.
Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet.

Read the instructions on the Answer Sheet very carefully.

Each correct answer will score one mark. A mark will not be deducted for a wrong answer.
Any rough working should be done in this booklet.
A copy of the Periodic Table is printed on page 16.
You may use a calculator.

This document consists of 16 printed pages.

IB12 06_0620_12/3RP
© UCLES 2012 [Turn over
2

1 Which diagram shows the process of diffusion?

key
A
different
atoms

2 Which method would be most suitable for the separation of a mixture of sand and water to obtain
the sand?

A chromatography
B crystallisation
C distillation
D filtration

3 A student investigates how the concentration of an acid affects the speed of reaction with a 0.5 g
mass of magnesium at 30 °C.

The student has a beaker, concentrated acid, water and the apparatus below.

P a balance
Q a clock
R a measuring cylinder
S a thermometer

Which pieces of apparatus does the student use?

A P, Q and R only
B P, Q and S only
C Q, R and S only
D P, Q, R and S

© UCLES 2012 0620/12/M/J/12

4 An element Y has the proton number 18.

The next element in the Periodic Table is an element Z.

Which statement is correct?

A Element Z has one more electron in its outer shell than element Y.
B Element Z has one more electron shell than element Y.
C Element Z is in the same group of the Periodic Table as element Y.
D Element Z is in the same period of the Periodic Table as element Y.

5 Which atom has twice as many neutrons as protons?

1 2 3 4
A 1H B 1H C 1H D 2 He

6 The table contains information about four substances.

Which substance is potassium chloride?

melting point conduction of electricity

/ °C when molten in aqueous solution

A 11 no yes
B 98 yes yes
C 772 yes yes
D 1410 no insoluble

7 The electronic structures of atoms P and Q are shown.

key
P Q = electron

P and Q react to form an ionic compound.

What is the formula of this compound?

A PQ2 B P2Q C P2Q6 D P6Q2

© UCLES 2012 0620/12/M/J/12 [Turn over

8 The diagrams show the structures of two forms, P and Q, of a solid element.

P Q

What are suitable uses of P and Q, based on their structures?

use of solid P use of solid Q

A drilling drilling
B lubricating drilling
C drilling lubricating
D lubricating lubricating

9 Methane, CH4, burns in the air to form carbon dioxide and water.

What is the balanced equation for this reaction?

A CH4(g) + O2(g) → CO2(g) + 2H2O(g)

B CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)

C CH4(g) + 2O2(g) → CO2(g) + H2O(g)

D CH4(g) + 3O2(g) → CO2(g) + 2H2O(g)

10 In which reaction is lead(II) oxide, PbO, oxidised?

A PbO + C → Pb + CO

B PbO + CO → Pb + CO2

C PbO + H2 → Pb + H2O

D 2PbO + O2 → 2PbO2

© UCLES 2012 0620/12/M/J/12

11 The diagram shows an unsuccessful experiment to nickel plate a pan.

–ve +ve

nickel cathode pan

nickel sulfate
solution

Which change is necessary to plate the pan with nickel?

A Add more nickel sulfate to the solution.

B Heat the solution to 100 °C.

C Increase the current in the circuit.
D Make the pan the negative electrode.

12 The rates of some chemical reactions can be measured by using the apparatus shown.

reactants

94.72 g balance

For which reaction is this apparatus suitable?

A MgCO3 + 2HCl → MgCl 2 + CO2 + H2O

B Mg + ZnCl 2 → MgCl 2 + Zn

C MgCl 2 + 2NaOH → Mg(OH)2 + 2NaCl

D MgO + 2HCl → MgCl 2 + H2O

© UCLES 2012 0620/12/M/J/12 [Turn over

13 The diagram shows that two gases are formed when concentrated hydrochloric acid is
electrolysed using inert electrodes.

+ve –ve

concentrated
hydrochloric acid

Which row correctly describes the colours of the gases at the electrodes?

anode (+ve) cathode (–ve)

A colourless colourless
B colourless yellow-green
C yellow-green colourless
D yellow-green yellow-green

14 The diagram shows the reaction between zinc oxide and dilute hydrochloric acid.

zinc oxide powder

dilute aqueous
hydrochloric acid zinc chloride
20 °C 22 °C
pH 1 pH 7

before after

Which terms describe the reaction?

endothermic neutralisation

A
B
C
D

© UCLES 2012 0620/12/M/J/12

15 Four different gases are passed through the apparatus shown.

gas in gas out

damp red damp blue

litmus paper litmus paper

Which gas has no effect on either piece of litmus paper?

A ammonia
B carbon dioxide
C chlorine
D hydrogen

16 An aqueous solution of copper(II) sulfate was made by adding excess copper(II) oxide to dilute
sulfuric acid. The mixture was heated, stirred and then filtered.

dilute copper(II) sulfate

sulfuric acid solution

copper(II) oxide

heat

What was the pH of the acid before adding the copper(II) oxide and of the solution after filtration?

pH of acid before adding pH of solution

copper(II) oxide after filtration

A greater than 7 7
B greater than 7 less than 7
C less than 7 7
D less than 7 greater than 7

© UCLES 2012 0620/12/M/J/12 [Turn over

17 Aqueous potassium iodide is added to aqueous silver nitrate.

What are the colours of the final precipitate and solution?

precipitate solution

A brown colourless
B white yellow
C yellow colourless
D yellow white

18 Three gas jars contain carbon dioxide, hydrogen and oxygen, as shown.

carbon dioxide hydrogen oxygen

Which one of the following tests could be used to discover which gas is in each jar?

A a glowing splint
B a lighted splint
C damp blue litmus paper
D limewater

19 The diagram shows an outline of part of the Periodic Table.

X
Y Z

Which statement about elements X, Y and Z is not correct?

A All are metals.

B All conduct electricity.
C All form coloured compounds.
D All react with oxygen.

© UCLES 2012 0620/12/M/J/12

20 Elements X, Y and Z are in Group VII of the Periodic Table.

X is a gas.

Y is less reactive than Z

Z is a red liquid.

When X, Y and Z are put in order of increasing proton number, which order is correct?

A X→Y→Z B X→Z→Y C Y→X→Z D Y→Z→X

21 Which properties of the element titanium, Ti, can be predicted from its position in the Periodic
Table?

can be used conducts electricity forms coloured

has low density
as a catalyst when solid compounds

A
B
C
D

22 Five elements have proton numbers 10, 12, 14, 16 and 18.

What are the proton numbers of the three elements that form oxides?

A 10, 12 and 14
B 10, 14 and 18
C 12, 14 and 16
D 14, 16 and 18

23 Which statement about aluminium is not correct?

A It is resistant to corrosion.
B It is strong and has a high density.
C It is used in food containers.
D It is used in the manufacture of aircraft.

© UCLES 2012 0620/12/M/J/12 [Turn over

24 Many metals are extracted from their ores by heating the metal oxide with carbon.

Which metal cannot be extracted using this method?

A aluminium
B copper
C iron
D zinc

25 A metal has the following properties.

● It does not react with cold water.

● It reacts with dilute hydrochloric acid.
● It cannot be extracted from its oxide using carbon.

Between which two metals in the reactivity series should it be placed?

A calcium and magnesium

B iron and copper
C magnesium and zinc
D zinc and iron

26 Which statements about the general properties of metals are correct?

1 conduct electricity when solid

2 form acidic oxides
3 high melting point

A 1 and 3 B 1 only C 2 and 3 D 2 only

27 Water for human use is treated by filtration then chlorination.

Which uses do not need water of this quality?

1 water for cooling in industry

2 water for flushing toilets in the home
3 water for drinking

A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

© UCLES 2012 0620/12/M/J/12

28 Carbon monoxide is an air pollutant produced when petrol is burned in a car engine.

Why is carbon monoxide considered to be an air pollutant?

A It causes global warming.

B It causes the corrosion of buildings.
C It is a greenhouse gas.
D It is poisonous.

29 A new planet has been discovered and its atmosphere has been analysed.

atmosphere

planet

The table shows the composition of the atmosphere.

gas percentage by volume

carbon dioxide 4
nitrogen 72
oxygen 24

Which gases are present in the atmosphere of the planet in a higher percentage than they are in
the Earth’s atmosphere?

A carbon dioxide and oxygen

B carbon dioxide only
C nitrogen and oxygen
D nitrogen only

30 Acetylene, C2H2, is a hydrocarbon. When acetylene and oxygen react, the hot flame produced
can be used to weld steel.

Which statement is correct?

A Acetylene and oxygen react exothermically.

B Acetylene is saturated.
C Oxygen and steel react endothermically.
D Oxygen is a gaseous fuel.

© UCLES 2012 0620/12/M/J/12 [Turn over

31 Fertilisers are used to provide three elements needed to increase the yield of crops.

Which two compounds, when used together, would provide all three of these elements?

A ammonium nitrate and calcium phosphate

B ammonium nitrate and potassium sulfate
C potassium nitrate and calcium phosphate
D potassium nitrate and potassium sulfate

32 Carbon dioxide and methane are ‘greenhouse gases’ which contribute to global warming.

Which process does not increase global warming?

A burning fossil fuels

B decay of organic waste
C farming cattle for beef
D growing crops such as sugar cane

33 When coal and oil burn in power stations, the acidic gas sulfur dioxide is formed. Sulfur dioxide is
removed by absorbing it in a liquid sprayed down a tower.

liquid X
tower

spray

waste gases
(including sulfur dioxide)

What is liquid X?

A calcium hydroxide solution

B sodium chloride solution
C dilute hydrochloric acid
D water

© UCLES 2012 0620/12/M/J/12

34 The table shows bonds that are present and bonds that are not present in compound X.

bond

C–C
C=C
C–H
C–O
C=O
O–H

What type of compound is X?

A a carboxylic acid
B an alcohol
C an alkane
D an alkene

35 The diagram shows different fuels from which electricity can be generated.

diesel oil electricity uranium

coal

Which box completes the diagram?

A B C D

ammonia bitumen natural gas steam

© UCLES 2012 0620/12/M/J/12 [Turn over

36 The diagram shows apparatus used to separate petroleum into four fractions.

thermometer

petroleum
on rock wool

water

heat

fraction

Which fraction contains the smallest hydrocarbon molecules?

fraction boiling point range / °C

A up to 70
B 70 to 120
C 120 to 170
D over 170

37 Ethanol is a fuel used in cars. It can be made from petroleum.

C4H10 → C2H4 + C2H6 cracking

C2H4 + H2O → C2H5OH producing ethanol

C2H5OH + 3O2 → 2CO2 + 3H2O burning

Compounds of how many homologous series appear in these equations?

A 1 B 2 C 3 D 4

© UCLES 2012 0620/12/M/J/12

38 Butene is an alkene which is manufactured by cracking hydrocarbons.

H H H H

H C C C C

H H H

Which hydrocarbon can be cracked to make butene?

A ethane, C2H6
B decane, C10H22
C methane, CH4
D propane, C3H8

39 Which substance does not produce carbon dioxide when it burns in oxygen?

A butane
B ethanol
C ethene
D hydrogen

40 Ethanol is an important chemical produced by the ……1…… of ……2…… .

Which words correctly complete gaps 1 and 2?

1 2

A combustion ethane
B combustion glucose
C fermentation ethane
D fermentation glucose

© UCLES 2012 0620/12/M/J/12

7 9 11 12 14 16 19 20
Li Be B C N O F Ne
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
3 4 5 6 7 8 9 10

23 24 27 28 31 32 35.5 40
Na Mg Al Si P S Cl Ar
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
11 12 13 14 15 16 17 18

39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton

publisher will be pleased to make amends at the earliest possible opportunity.

19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
16

85 88 89 91 93 96 101 103 106 108 112 115 119 122 128 127 131

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

0620/12/M/J/12
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

133 137 139 178 181 184 186 190 192 195 197 201 204 207 209

Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Caesium Barium Lanthanum Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury Thallium Lead Bismuth Polonium Astatine Radon
55 56 57 * 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86

226 227
Fr Ra Ac

Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
Francium Radium Actinium
87 88 89

140 141 144 150 152 157 159 162 165 167 169 173 175
*58-71 Lanthanoid series
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
90-103 Actinoid series Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium
58 59 60 61 62 63 64 65 66 67 68 69 70 71
a a = relative atomic mass 232 238
Key X X = atomic symbol Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium
b b = proton (atomic) number 90 91 92 93 94 95 96 97 98 99 100 101 102 103

The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).

Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every

University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of
reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education
*7086809263*

CHEMISTRY 0620/22
Paper 2 May/June 2012
1 hour 15 minutes
Candidates answer on the Question Paper.
No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Write your Centre number, candidate number and name in the spaces at the top of this page.
Write in dark blue or black pen.
You may need to use a pencil for any diagrams, graphs or rough working.
Do not use staples, paper clips, highlighters, glue or correction fluid.
DO NOT WRITE IN ANY BARCODES.

Answer all questions.

A copy of the Periodic Table is printed on page 16.

At the end of the examination, fasten all your work securely together. For Examiner’s Use
The number of marks is given in brackets [ ] at the end of each question or part
question. 1

Total

This document consists of 14 printed pages and 2 blank pages.

IB12 06_0620_22/3RP
© UCLES 2012 [Turn over
2
For
1 (a) Gases can be identified by carrying out particular tests. Examiner’s
Some gases and tests to identify them are shown below. Use

Match the gases on the left with the tests on the right.
The first one has been done for you.

sulfur dioxide turns limewater milky

turns potassium
carbon dioxide
dichromate green

‘pops’ with a
chlorine
lighted splint

oxygen relights a glowing splint

bleaches damp
hydrogen
litmus paper

[4]

(b) Chlorine can be prepared by heating hydrochloric acid with manganese(IV) oxide.

MnO2 + 4HCl → MnCl 2 + Cl 2 + 2H2O

(i) Write a word equation for this reaction.

[3]

© UCLES 2012 0620/22/M/J/12

3
For
(ii) Chlorine is Examiner’s
Use
● denser than air
● soluble in water.

Which one of the following diagrams, A, B or C, best describes how chlorine gas is
collected?

A B C

water

Answer = ......................... [1]

(c) Hydrogen reacts with oxygen to form water.

(i) Complete the equation for this reaction.

2H2 + ....... → .....H2O

[2]

(ii) State one use of

hydrogen, ...................................................................................................................

water. ................................................................................................................... [2]

[Total: 12]

© UCLES 2012 0620/22/M/J/12 [Turn over

4
For
2 Alkalis are soluble bases. Examiner’s
Use
(a) Which one of the following is alkaline?
Put a ring around the correct answer.

distilled water hydrochloric acid

sodium chloride solution sodium hydroxide solution

[1]

(b) Suggest a pH value for a solution which is alkaline.

..................................................................................................................................... [1]

(c) Describe how you would find the pH of a solution.

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

..................................................................................................................................... [2]

(d) When excess fertilisers are put on the soil, the soil may become acidic.

(i) Why is it important to farmers that the soil does not become too acidic?

.............................................................................................................................. [1]

(ii) Calcium carbonate is used to decrease the acidity of the soil. Explain how calcium
carbonate decreases soil acidity.

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

.............................................................................................................................. [2]

[Total: 7]

© UCLES 2012 0620/22/M/J/12

5
For
3 The table below shows some properties of the halogens. Examiner’s
Use
halogen melting point / °C boiling point / °C colour

chlorine –101 –35

bromine –7 +59
iodine +114 +184 greyish-black

(a) (i) Complete the spaces in the table to show the colours of chlorine and bromine. [2]

(ii) Room temperature is about 20 °C.

Use the information in the table to explain why

chlorine is a gas at room temperature, ......................................................................

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

bromine is a liquid at room temperature. ...................................................................

.............................................................................................................................. [2]

(iii) Astatine is the halogen below iodine in the Periodic Table.

Suggest a value for the melting point of astatine.

.............................................................................................................................. [1]

(b) Chlorine reacts with an aqueous solution of potassium iodide.

(i) Complete the balanced equation for this reaction.

Cl 2 + .....KI → 2KCl + .......

[2]

(ii) State the names of the products of this reaction.

.............................................................................................................................. [2]

(iii) To which period in the Periodic Table does chlorine belong?

.............................................................................................................................. [1]

hydrochloric nitric potassium precipitate

silver solution white yellow

A small volume of solution containing aqueous iodide ions is put into a test-tube. Dilute
........................ acid is added followed by a few drops of ........................ nitrate solution.
A ........................ coloured ........................ is formed if iodide ions are present. [4]

[Total: 14]

© UCLES 2012 0620/22/M/J/12 [Turn over

6
For
4 The diagram below shows the structure of some substances containing nitrogen. Examiner’s
Use
A B C

N
N N H H NH4+ NO3– NH4+ NO3–
H
NO3– NH4+ NO3– NH4+

NH4+ NO3– NH4+ NO3–

D E

H 2N CH2 COOH N
Cl Cl
Cl

(a) (i) Which one of these substances, A, B, C, D or E, is an alkaline gas?

(ii) Which one of these substances is an ionic salt?

(iii) Which one of these substances contains a carboxylic acid functional group?

[3]

(b) Oxides of nitrogen such as nitrogen dioxide, NO2, are atmospheric pollutants.
Give one source of nitrogen oxides in the air.

..................................................................................................................................... [1]

(c) State one harmful effect of nitrogen dioxide.

..................................................................................................................................... [1]

(d) Calculate the relative formula mass of nitrogen dioxide, NO2.

[1]

(e) In the presence of a catalyst, nitrogen dioxide reacts with carbon monoxide.

2NO2 + 4CO → N2 + 4CO2

(i) Which substance gets oxidised during this reaction? Explain your answer.

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

.............................................................................................................................. [2]

© UCLES 2012 0620/22/M/J/12

7
For
(ii) What is the meaning of the term catalyst ? Examiner’s
Use
.............................................................................................................................. [1]

(iii) Carbon monoxide is formed when some of the air holes in a water heater get blocked.
The diagram shows a water heater.

combustion products

hot water out

cold water in gas burning in air

air holes

Explain why carbon monoxide is formed when some of the air holes in a water
heater get blocked.

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

.............................................................................................................................. [2]

(iv) Explain why carbon monoxide is dangerous.

.............................................................................................................................. [1]

[Total: 12]

© UCLES 2012 0620/22/M/J/12 [Turn over

8
For
5 Iron is a shiny metallic solid. Iron is a transition element. Examiner’s
Use
(a) State three other physical properties of a transition element.

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

..................................................................................................................................... [3]

(b) Iron reacts with sulfuric acid.

Fe + H2SO4 → FeSO4 + H2

(i) Write a word equation for this reaction.

.............................................................................................................................. [2]

(ii) Describe, with the aid of a diagram, how you could measure the speed of this
reaction.
In your answer describe:

● the apparatus you would use

● the measurements you would take.

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

.............................................................................................................................. [4]

(c) When iron reacts with sulfur, energy is released.

(i) What is the name given to a reaction which releases energy?

.............................................................................................................................. [1]

© UCLES 2012 0620/22/M/J/12

9
For
(ii) The compound formed in this reaction is iron(II) sulfide. Examiner’s
What do you understand by the term compound ? Use

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

.............................................................................................................................. [1]

(iii) The diagram below shows the structure of iron(II) sulfide.

Fe atoms
S atoms

What is the simplest formula for iron(II) sulfide?

.............................................................................................................................. [1]

[Total: 12]

© UCLES 2012 0620/22/M/J/12 [Turn over

10
For
6 The diagram shows a fractionating column used to separate different hydrocarbon fractions Examiner’s
in an oil refinery. Use

fractions

refinery gas

gasoline

kerosene

diesel oil

fuel oil

lubricating oil
petroleum

bitumen

(a) On the diagram, draw an X to show the place in the column where the temperature is the
highest. [1]

(b) State the name of the fraction labelled A.

..................................................................................................................................... [1]

(c) State a use for

the kerosene fraction, .......................................................................................................

the diesel oil fraction. .................................................................................................. [2]

© UCLES 2012 0620/22/M/J/12

11
For
(d) Complete the following sentences about fractional distillation using words from the list Examiner’s
below. Use

boiling condenses cooled heated higher

lower melting mixture pressure vaporises

Petroleum is a ............................ of hydrocarbons. This mixture is ............................

and the hydrocarbons vaporise. The temperature in the fractionating column is

............................ at the top than at the bottom. As the vapours move up the column,

each hydrocarbon fraction ............................ when the temperature in the column falls

below the ............................ point of the hydrocarbon fraction. [5]

(e) The structures of four hydrocarbons, A, B, C and D, are shown below.

A B

H H H H H H H

H C C C H H C C C C H

H H H H H

C D

H H H H H H H

H C C C H C C C C H
H H H H H
H C H

(i) Which two of these structures A, B, C or D have the same relative molecular mass?

.......................................................... and .......................................................... [1]

(ii) Which two of these structures A, B, C or D will decolourise aqueous bromine?

.......................................................... and .......................................................... [2]

[Total: 12]

© UCLES 2012 0620/22/M/J/12 [Turn over

12
For
7 A student placed some crystals of salt at the bottom of a beaker of distilled water. She left the Examiner’s
contents of the beaker to stand for one hour. Use
The diagram below shows her observations.

distilled water
X

salt crystals
at start after 15 minutes after 1 hour

After one hour, all the salt had disappeared but the solution at point X tasted salty.

(a) Use the kinetic particle theory to explain these observations.

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

..................................................................................................................................... [4]

(b) Salt is sodium chloride, NaCl.

(i) Which one of the following statements about bond formation in sodium chloride is
true?
Tick one box.

A sodium atom shares one electron with a chlorine atom.

A sodium atom loses its outermost electron and a chlorine

atom gains an electron.

A sodium atom shares two electrons with a chlorine atom.

A sodium atom gains an electron and a chlorine atom

loses its outermost electrons.

[1]

© UCLES 2012 0620/22/M/J/12

13
For
(ii) Explain why solid sodium chloride does not conduct electricity but molten sodium Examiner’s
chloride does conduct. Use

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

.............................................................................................................................. [2]

(iii) State the name of the product formed at each electrode when a concentrated
aqueous solution of sodium chloride is electrolysed using graphite electrodes.

at the positive electrode .............................................................................................

at the negative electrode ..................................................................................... [2]

(iv) What is the name of the negative electrode?

Put a ring around the correct answer.

anion anode cation cathode electrolyte

[1]

(v) Suggest why graphite is a suitable material for an electrode.

.............................................................................................................................. [1]

[Total: 11]

© UCLES 2012 0620/22/M/J/12 [Turn over

BLANK PAGE

© UCLES 2012 0620/22/M/J/12

BLANK PAGE

© UCLES 2012 0620/22/M/J/12

7 9 11 12 14 16 19 20
Li Be B C N O F Ne
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
3 4 5 6 7 8 9 10

23 24 27 28 31 32 35.5 40
Na Mg Al Si P S Cl Ar
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
11 12 13 14 15 16 17 18

39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

publisher will be pleased to make amends at the earliest possible opportunity.

Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
16

85 88 89 91 93 96 101 103 106 108 112 115 119 122 128 127 131

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

0620/22/M/J/12
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

133 137 139 178 181 184 186 190 192 195 197 201 204 207 209

226 227
Fr Ra Ac

Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
Francium Radium Actinium
87 88 89

The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).

University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of
reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included the
Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education
*7023052942*

CHEMISTRY 0620/32
Paper 3 (Extended) May/June 2012
1 hour 15 minutes
Candidates answer on the Question Paper.
No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Write your Centre number, candidate number and name on all the work you hand in.
Write in dark blue or black pen.
You may use a pencil for any diagrams, graphs or rough working.
Do not use staples, paper clips, highlighters, glue or correction fluid.
DO NOT WRITE IN ANY BARCODES.

Answer all questions.

A copy of the Periodic Table is printed on page 12. For Examiner’s Use

At the end of the examination, fasten all your work securely together. 1
The number of marks is given in brackets [ ] at the end of each question or part
question. 2

Total

This document consists of 11 printed pages and 1 blank page.

IB12 06_0620_32/3RP
© UCLES 2012 [Turn over
2
For
1 The table below includes information about some of the elements in Period 2. Examiner’s
Use

element carbon nitrogen fluorine neon

symbol C N F Ne
structure macromolecular simple simple single
molecules N2 molecules F2 atoms Ne
boiling point / °C 4200 –196 –188 –246

(a) Why does neon exist as single atoms but fluorine exists as molecules?

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

..................................................................................................................................... [2]

(b) What determines the order of the elements in a period?

..................................................................................................................................... [1]

(c) When liquid nitrogen boils the following change occurs.

N2(l) → N2(g)

The boiling point of nitrogen is very low even though the bond between the atoms in a
nitrogen molecule is very strong. Suggest an explanation.

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

..................................................................................................................................... [2]

(d) Draw a diagram showing the arrangement of the outer shell (valency) electrons in a
molecule of nitrogen.

[2]

[Total: 7]

© UCLES 2012 0620/32/M/J/12

3
For
2 Diamond and graphite are different forms of the same element, carbon. Examiner’s
Explain the following in terms of their structure. Use

(a) Graphite is a soft material which is used as a lubricant.

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

..................................................................................................................................... [2]

(b) Diamond is a very hard material which is used for drilling and cutting.

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

..................................................................................................................................... [2]

(c) Graphite is a good conductor of electricity and diamond is a poor conductor.

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

..................................................................................................................................... [2]

[Total: 6]

3 The uses of a substance are determined by its properties.

(a) Plastics are poor conductors of electricity. They are used as insulation for electric cables.
Which other two properties of plastics make them suitable for this purpose?

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

..................................................................................................................................... [2]

(b) Chromium is a hard, shiny metal. Suggest two reasons why chromium is used to
electroplate steel.

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

..................................................................................................................................... [2]

(c) Why is aluminium used extensively in the manufacture of aeroplanes?

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

..................................................................................................................................... [2]

© UCLES 2012 0620/32/M/J/12 [Turn over

4
For
(d) Why is copper a suitable material from which to make cooking utensils? Examiner’s
Use
copper
cooking
utensil

food

heat

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

..................................................................................................................................... [2]

(e) Describe the bonding in a typical metal.

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

..................................................................................................................................... [2]

[Total: 10]

4 The ore of aluminium is bauxite which is impure aluminium oxide. Alumina, pure aluminium
oxide, is obtained from bauxite.
Aluminium is formed at the cathode when a molten mixture of alumina and cryolite, Na3Al F6,
is electrolysed.

(a) (i) Name two products formed at the anode in this electrolysis.

.............................................................................................................................. [2]

(ii) All the aluminium formed comes from the alumina not the cryolite.
Suggest two reasons why the electrolyte must contain cryolite.

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

.............................................................................................................................. [2]

(iii) The major impurity in bauxite is iron(III) oxide. Iron(III) oxide is basic, aluminium
oxide is amphoteric. Explain how aqueous sodium hydroxide can be used to separate
them.

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

.............................................................................................................................. [2]

© UCLES 2012 0620/32/M/J/12

5
For
(b) The purification of bauxite uses large amounts of sodium hydroxide. Examiner’s
Use
(i) Describe the chemistry of how sodium hydroxide is made from concentrated aqueous
sodium chloride. The description must include at least one ionic equation.

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

.............................................................................................................................. [5]

(ii) Making sodium hydroxide from sodium chloride produces two other chemicals.
Name these two chemicals and state one use of each chemical.

chemical ....................................................................................................................

use .............................................................................................................................

chemical ....................................................................................................................

use ....................................................................................................................... [2]

[Total: 13]

5 Islay is an island off the west coast of Scotland. The main industry on the island is making
ethanol from barley.

Barley contains the complex carbohydrate, starch. Enzymes catalyse the hydrolysis of starch
to a solution of glucose.

(a) (i) Draw the structure of the starch.

Glucose can be represented by HO OH

[2]

© UCLES 2012 0620/32/M/J/12 [Turn over

6
For
(ii) Enzymes can catalyse the hydrolysis of starch. Name another catalyst for this Examiner’s
reaction. Use

.............................................................................................................................. [1]

(iii) Both starch and glucose are carbohydrates. Name the elements found in all
carbohydrates.

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

.............................................................................................................................. [1]

(b) Yeast cells are added to the aqueous glucose. Fermentation produces a solution
containing up to 10 % of ethanol.

(i) Complete the word equation for the fermentation of glucose.

glucose → .......................... + ..........................

[1]

(ii) Explain why is it necessary to add yeast and suggest why the amount of yeast in the
mixture increases.

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

.............................................................................................................................. [2]

(iii) Fermentation is carried out at 35 °C. For many reactions a higher temperature would
give a faster reaction. Why is a higher temperature not used in this process?

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

.............................................................................................................................. [2]

(c) The organic waste, the residue of the barley and yeast, is disposed of through a pipeline
into the sea. In the future this waste will be converted into biogas by the anaerobic
respiration of bacteria. Biogas, which is mainly methane, will supply most of the island’s
energy.

(i) Anaerobic means in the absence of oxygen. Suggest an explanation why oxygen
must be absent.

.............................................................................................................................. [1]

(ii) The obvious advantage of converting the waste into methane is economic.
Suggest two other advantages.

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

.............................................................................................................................. [2]

[Total: 12]

© UCLES 2012 0620/32/M/J/12

7
For
6 A length of magnesium ribbon was added to 50 cm3 of sulfuric acid, concentration Examiner’s
1.0 mol / dm3. The time taken for the magnesium to react was measured. The experiment was Use
repeated with the same volume of different acids. In all these experiments, the acid was in
excess and the same length of magnesium ribbon was used.

(a)
concentration
experiment acid time / s
in mol / dm3

A sulfuric acid 1.0 20

B propanoic acid 0.5 230
C hydrochloric acid 1.0 40
D hydrochloric acid 0.5 80

(i) Write these experiments in order of reaction speed. Give the experiment with the
fastest speed first.

.............................................................................................................................. [1]

(ii) Give reasons for the order you have given in (i).

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

.............................................................................................................................. [5]

(b) Suggest two changes to experiment C which would increase the speed of the reaction
and explain why the speed would increase. The volume of the acid, the concentration of
the acid and the mass of magnesium used were kept the same.

change 1 ...........................................................................................................................

explanation .......................................................................................................................

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

change 2 ...........................................................................................................................

explanation .......................................................................................................................

..................................................................................................................................... [5]

[Total: 11]

© UCLES 2012 0620/32/M/J/12 [Turn over

8
For
7 The alkenes are unsaturated hydrocarbons. They form a homologous series, the members of Examiner’s
which have similar chemical properties: Use

● easily oxidised
● addition reactions
● polymerisation
● combustion.

(a) All the alkenes have the same empirical formula.

(i) State their empirical formula.

.............................................................................................................................. [1]

(ii) Why is the empirical formula the same for all alkenes?

.............................................................................................................................. [1]

(b) Alkenes can be oxidised to carboxylic acids by boiling with aqueous potassium
manganate(VII).

(i) Pent-2-ene, CH3–CH2–CH=CH–CH3, oxidises to CH3–CH2–COOH and CH3COOH.

Name these two acids.

CH3–CH2–COOH .......................................................................................................

CH3COOH ............................................................................................................ [2]

(ii) Most alkenes oxidise to two carboxylic acids. Deduce the formula of an alkene which
forms only one carboxylic acid.

[1]

(i) CH3–CH=CH2 + Br2 → .................................... [1]

(ii) CH3–CH=CH2 + H2O → .................................... [1]

(d) Draw the structural formula of poly(propene)

[2]

© UCLES 2012 0620/32/M/J/12

9
For
(e) 0.01 moles of an alkene needed 2.4 g of oxygen for complete combustion. 2.2 g of carbon Examiner’s
dioxide were formed. Determine the following mole ratio. Use

moles of alkene : moles of O2 : moles of CO2

From this ratio determine the formula of the alkene.

..................................................................................................................................... [3]

Write an equation for the complete combustion of this alkene.

..................................................................................................................................... [1]

[Total: 13]

8 Ethylamine, CH3–CH2–NH2, is a base which has similar properties to ammonia.

(a) In aqueous ethylamine, there is the following equilibrium.

CH3–CH2–NH2 + H2O CH3–CH2–NH3+ + OH–

Explain why water is behaving as an acid in this reaction.

..................................................................................................................................... [1]

(b) Given aqueous solutions of ethylamine and sodium hydroxide, describe how you could
show that ethylamine is a weak base like ammonia and not a strong base like sodium
hydroxide.

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

..................................................................................................................................... [3]

(c) Ethylamine, like ammonia, reacts with acids to form salts.

CH3–CH2–NH2 + HCl → CH3–CH2–NH3Cl

ethylammonium chloride

Suggest how you could displace ethylamine from the salt, ethylammonium chloride.

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

..................................................................................................................................... [2]

© UCLES 2012 0620/32/M/J/12 [Turn over

10
For
(d) Explain the chemistry of the following reaction: Examiner’s
Use
When aqueous ethylamine is added to aqueous iron(III) chloride, a brown precipitate is
formed.

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

..................................................................................................................................... [2]

[Total: 8]

© UCLES 2012 0620/32/M/J/12

BLANK PAGE

© UCLES 2012 0620/32/M/J/12

7 9 11 12 14 16 19 20
Li Be B C N O F Ne
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
3 4 5 6 7 8 9 10

23 24 27 28 31 32 35.5 40
Na Mg Al Si P S Cl Ar
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
11 12 13 14 15 16 17 18

39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

publisher will be pleased to make amends at the earliest possible opportunity.

85 88 89 91 93 96 101 103 106 108 112 115 119 122 128 127 131

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

0620/32/M/J/12
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

133 137 139 178 181 184 186 190 192 195 197 201 204 207 209

226 227
Fr Ra Ac

Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
Francium Radium Actinium
87 88 89

The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).

University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of
reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included the
Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education
*1869046502*

CHEMISTRY 0620/52
Paper 5 Practical Test May/June 2012
1 hour 15 minutes
Candidates answer on the Question Paper.
Additional Materials: As listed in the Confidential Instructions

READ THESE INSTRUCTIONS FIRST

Answer all questions.

Practical notes are provided on page 8.

At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question or part question.

For Examiner’s Use

Total

This document consists of 7 printed pages and 1 blank page.

IB12 06_0620_52/RP
© UCLES 2012 [Turn over
2
For
1 You are going to investigate what happens when two different solids, C and D, dissolve in Examiner’s
water. Use

Read all the instructions below carefully before starting the experiments.

Instructions
You are going to carry out two experiments.

(a) Experiment 1

Place the polystyrene cup in the 250 cm3 beaker for support.

Use a measuring cylinder to pour 25 cm3 of distilled water into the polystyrene cup.
Measure the temperature of the water and record it in the table below.

Add all of solid C to the water, start the timer and stir the mixture with the thermometer.

Measure the temperature of the solution every 30 seconds for three minutes. Record
your results in the table.

time / s 0 30 60 90 120 150 180

temperature of solution / °C
[2]

(b) Experiment 2

Empty the polystyrene cup and rinse it with water.

Use a measuring cylinder to pour 25 cm3 of distilled water into the polystyrene cup.
Measure the temperature of the water and record it in the table below.

Add all of solid D to the water, start the timer and stir the mixture with the thermometer.

Measure the temperature of the solution every 30 seconds for three minutes. Record
your results in the table.

time / s 0 30 60 90 120 150 180

temperature of solution / °C
[2]

© UCLES 2012 0620/52/M/J/12

3
For
(c) Plot the results for Experiments 1 and 2 on the grid and draw two smooth line graphs. Examiner’s
Clearly label your graphs. Use
temperature of solution / °C

0 30 60 90 120 150 180

time / s
[6]

(d) (i) From your graph, deduce the temperature of the solution in Experiment 1 after
45 seconds.
Show clearly on the graph how you worked out your answer.

.......................... °C [2]

(ii) From your graph, deduce how long it takes for the initial temperature of the solution
in Experiment 2 to change by 1 °C.
Show clearly on the graph how you worked out your answer.

.......................... s [2]

© UCLES 2012 0620/52/M/J/12 [Turn over

4
For
(e) What type of change occurs when substance D dissolves in water? Examiner’s
Use
..................................................................................................................................... [1]

(f) Suggest and explain the effect on the results if Experiment 1 was repeated using 50 cm3
of distilled water.

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

..................................................................................................................................... [2]

(g) Predict the temperature of the solution in Experiment 2 after 1 hour. Explain your answer.

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

..................................................................................................................................... [2]

(h) When carrying out the experiments, what would be the advantage of taking the
temperature readings every 15 seconds?

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

..................................................................................................................................... [2]

[Total: 21]

© UCLES 2012 0620/52/M/J/12

5
For
2 You are provided with solid E and liquid F. Examiner’s
Carry out the following tests on E and F, recording all of your observations in the table. Use
Conclusions must not be written in the table.

tests observations
tests on solid E

(a) Describe the appearance of solid E.

................................................................ [1]

(b) Place half of solid E in a test-tube. Heat

the test-tube gently. ......................................................................

Test any gas given off. ................................................................ [3]

(c) (i) Add half of the remaining solid E to ......................................................................

about 5 cm3 of dilute sulfuric acid in a
test-tube. ................................................................ [2]

Allow the mixture to settle. Decant off

the liquid into a test-tube.

Divide the solution into two equal

portions in test-tubes. Add 1 cm
depth of distilled water to each
test-tube and shake. Carry out the
following tests.

(ii) Add several drops of aqueous sodium

hydroxide to the first portion of the
solution and shake the test-tube. ......................................................................
Now add excess sodium hydroxide to
the test-tube. ................................................................ [2]

(iii) Add several drops of aqueous

ammonia to the second portion of the ......................................................................
solution and shake the test-tube.
Now add excess aqueous ammonia ......................................................................
to the test-tube.
................................................................ [3]

© UCLES 2012 0620/52/M/J/12 [Turn over

6
For
tests observations Examiner’s
Use
tests on liquid F

(d) Describe the appearance and smell of

liquid F. appearance ............................................ [1]

smell ....................................................... [1]

(e) Use pH indicator paper to measure the pH

of liquid F. pH .......................................................... [1]

(f) Add about 3 cm3 of liquid F to the rest of ......................................................................

solid E in a test-tube. Leave to stand for
five minutes. ................................................................ [2]

(g) Identify solid E.

..................................................................................................................................... [2]

(h) Draw one conclusion about liquid F.

..................................................................................................................................... [1]

[Total: 19]

© UCLES 2012 0620/52/M/J/12

BLANK PAGE

© UCLES 2012 0620/52/M/J/12

NOTES FOR USE IN QUALITATIVE ANALYSIS

Test for anions

anion test test result

carbonate (CO32–) add dilute acid effervescence, carbon dioxide
produced
chloride (Cl –) acidify with dilute nitric acid, then white ppt.
[in solution] add aqueous silver nitrate
iodide (I–) acidify with dilute nitric acid, then yellow ppt.
[in solution] add aqueous silver nitrate
nitrate (NO3–) add aqueous sodium hydroxide ammonia produced
[in solution] then aluminium foil; warm carefully
sulfate (SO42–) acidify with dilute nitric acid, then white ppt.
[in solution] aqueous barium nitrate

Test for aqueous cations

cation effect of aqueous sodium hydroxide effect of aqueous ammonia

white ppt., soluble in excess giving white ppt., insoluble in excess
aluminium (Al 3+)
a colourless solution
ammonium (NH4+) ammonia produced on warming –
calcium (Ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt.
copper (Cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess
giving a dark blue solution
iron(II) (Fe2+) green ppt., insoluble in excess green ppt., insoluble in excess
iron(III) (Fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess
zinc (Zn2+) white ppt., soluble in excess giving white ppt., soluble in excess giving
a colourless solution a colourless solution

Test for gases

gas test and test results

ammonia (NH3) turns damp red litmus paper blue
carbon dioxide (CO2) turns limewater milky
chlorine (Cl 2) bleaches damp litmus paper
hydrogen (H2) ‘pops’ with a lighted splint
oxygen (O2) relights a glowing splint

Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every
reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included the
publisher will be pleased to make amends at the earliest possible opportunity.

University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of
Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.

© UCLES 2012 0620/52/M/J/12

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

CHEMISTRY 0620/52
Paper 5 Practical Test May/June 2012

CONFIDENTIAL INSTRUCTIONS
Great care should be taken to ensure that any confidential information given does not reach the
*3690773667*

candidates either directly or indirectly.

READ THESE INSTRUCTIONS FIRST

The teacher responsible for preparing the examination is not allowed to consult the question paper before the
examination. Teachers should, as part of the preparation of the examination requirements, carry out any tests
indicated on page 2 in order to satisfy themselves that the supplied materials are satisfactory.

The standard Report Form to be included with the scripts is given on pages 7 and 8. Please detach and
enclose it with the scripts. If scripts are despatched in more than one envelope, it is essential that a copy of
the Supervisor’s Results and of the Report Form are sent inside each envelope.

More material may be issued if required, without penalty, but this should not be necessary. Safety spectacles
may be provided if considered necessary.

Supervisors are advised to remind candidates that all substances in the examination should be treated with
caution. Please also see under ‘General Apparatus’ on the use of pipette fillers and safety goggles.

In accordance with COSHH (Control of Substances Hazardous to Health) Regulations, operative in the UK, a
hazard appraisal of the examination has been carried out.

Attention is drawn, in particular, to certain materials used in the examination. The following codes are used
where relevant.

C = corrosive substance F = highly flammable substance

H = harmful or irritating substance O = oxidising substance

N = harmful to the environment T = toxic substance

Hazard data sheets should be available from your suppliers.

If you have any queries regarding these Instructions, please contact CIE
by e-mail: International@cie.org.uk,
by phone: +44 1223 553554,
by fax: +44 1223 553558,
stating the Centre number, the nature of the query and the syllabus number quoted above.

This document consists of 5 printed pages and 3 blank pages.

IB12 06_0620_52CI/2RP
© UCLES 2012 [Turn over
2

For Question 1

Each candidate will require

(a) one 25 cm3 or 50 cm3 measuring cylinder

(b) one beaker, 250 cm3, to support the polystyrene cup

(c) one polystyrene cup

(d) 3 g of anhydrous magnesium sulfate, MgSO4, in a dry stoppered tube, labelled solid C

(e) 6 g of hydrated magnesium sulfate crystals, MgSO4.7H2O, in a stoppered tube, labelled solid D

(f) access to water and distilled water

(g) one stirring thermometer, 0–110 °C

(h) a stop clock or timer

Note: The anhydrous magnesium sulfate, solid C, should be newly purchased to ensure that it
is anhydrous.

© UCLES 2012 0620/52/CI/M/J/12

For Question 2

Each candidate will require

[H] (a) a stoppered tube containing about 1 g of basic copper carbonate, CuCO3.Cu(OH)2, labelled
solid E

(b) a stoppered tube containing about 10 cm3 of ethanoic acid of concentration 1 mol / dm3,
labelled solution F

(c) pH indicator papers and chart

(d) rack of test-tubes

(e) distilled water

(f) splints

(g) limewater

(h) cork or bung to fit test-tubes

[C] (i) aqueous sodium hydroxide of concentration 1.0 mol / dm3

(j) aqueous ammonia of concentration 1.0 mol / dm3

[H] (k) aqueous sulfuric acid of concentration 0.5 mol / dm3

(l) spatula

(m) one 10 cm3 measuring cylinder

(n) a Bunsen burner and matches

(o) teat pipettes

Labels do not need to include concentrations.

© UCLES 2012 0620/52/CI/M/J/12

THE SUPERVISOR’S REPORT IS ON PAGES 7 AND 8

© UCLES 2012 0620/52/CI/M/J/12

THE SUPERVISOR’S REPORT IS ON PAGES 7 AND 8

© UCLES 2012 0620/52/CI/M/J/12

THE SUPERVISOR’S REPORT IS ON PAGES 7 AND 8

© UCLES 2012 0620/52/CI/M/J/12

This form must be completed and returned in the envelope with the scripts.

REPORT ON PRACTICAL CHEMISTRY

JUNE 2012

1 (a) Supervisor’s Results

It is recommended that the Supervisor should be a chemistry teacher.

The Supervisor is asked to carry out the experiments in Questions 1 and 2 and to record
the results on a spare copy of the question paper clearly labelled ‘Supervisor’s Results’.
Failure to enclose these results and this report form may lead to candidates being unavoidably
penalised.

(b) The candidate numbers of candidates in each session were:

First session Second session

© UCLES 2012 0620/52/CI/M/J/12

2 The Supervisor is invited to report details of any difficulties experienced by candidates giving names
and candidate numbers. The report should include reference to:

(a) any general difficulties encountered in making preparations for the examination;

(b) difficulties due to faulty apparatus or materials;

(c) accidents to apparatus or materials.

Other cases of individual hardship, e.g. illness, temporary disability, should be reported direct to
UCLES on the normal Application for Special Consideration form.

NAME OF CENTRE ...............................................................................................................................

CENTRE NUMBER ...................................................

SIGNED .......................................................
Supervisor

DECLARATION (to be signed by the Principal)

The preparation of this practical examination has been carried out so as to maintain fully the security
of the examination.

NAME .....................................................................................................................................................
(in block capitals)

SIGNED .............................................................................................................................. (Principal)

© UCLES 2012 0620/52/CI/M/J/12

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education
*8566192908*

CHEMISTRY 0620/62
Paper 6 Alternative to Practical May/June 2012
1 hour
Candidates answer on the Question Paper.
No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Answer all questions.

At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question or part For Examiner’s Use
question.
1

Total

This document consists of 12 printed pages.

IB12 06_0620_62/4RP
© UCLES 2012 [Turn over
2
For
1 A student heated red crystals of hydrated cobalt(II) chloride, CoCl 2.6H2O, to obtain a sample Examiner’s
of water. He used two different sets of apparatus, A and B. Use

cobalt chloride crystals

boiling tube

heat

water
cold water

boiling tube
cobalt chloride crystals

water
cold water
heat

(a) Complete the box to identify the piece of apparatus labelled. [1]

(b) The steam could have been condensed more efficiently using a condenser.
Draw a labelled diagram of a condenser.

[2]

© UCLES 2012 0620/62/M/J/12

3
For
(c) The colour of the solid remaining in the boiling tube after heating was blue. Examiner’s
Predict the effect of adding water to this solid. Explain your answer. Use

effect .................................................................................................................................

explanation ................................................................................................................. [2]

(d) Suggest why the boiling tube cracked using set of apparatus B but not set A.

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

..................................................................................................................................... [2]

[Total: 7]

© UCLES 2012 0620/62/M/J/12 [Turn over

4
For
2 An experiment was carried out to measure the speed (rate) of reaction between magnesium Examiner’s
carbonate and excess dilute nitric acid. Use
50 cm3 of dilute nitric acid was poured into a conical flask and placed on a balance. 1.0 g of
powdered magnesium carbonate was added to the flask. The mass of the flask and contents
decreased as a gas was given off. The loss in mass was recorded every half minute for six
minutes.

The results of the experiment are shown plotted on the grid below.

0.5

0.4

0.3
loss in
mass / g

0.2

0.1

0.0
0 1 2 3 4 5 6
time / minutes

(a) Draw a smooth line graph through the points. [1]

(b) Which point appears to be inaccurate?

..................................................................................................................................... [1]

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

..................................................................................................................................... [2]

(d) On the grid, sketch the graph you would expect if the reaction was repeated using 0.5 g
of lumps of magnesium carbonate. [2]

[Total: 6]

© UCLES 2012 0620/62/M/J/12

5
For
3 Electricity was passed through a solution of concentrated hydrochloric acid as shown below. Examiner’s
Use

concentrated
hydrochloric acid

Bubbles were observed at both electrodes.

(a) Give one other expected observation.

..................................................................................................................................... [1]

(b) Label the electrodes. [1]

.............................................................................................................................. [1]

(ii) Give a test for this gas.

test .............................................................................................................................

result .................................................................................................................... [2]

(d) Suggest why, at the beginning of the electrolysis, no gas was collected at the anode
(positive electrode).

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

..................................................................................................................................... [2]

[Total: 7]

© UCLES 2012 0620/62/M/J/12 [Turn over

6
For
4 A student investigated a reaction between a solid and a liquid. The reaction produced a gas. Examiner’s
She wanted to know if any of the substances W, X and Y were catalysts for the reaction. Use
Firstly she carried out the reaction without any W, X or Y.
Then she repeated the reaction three times adding a small amount of W, X or Y. In each case
she timed how long the reaction took to finish. The results are in the table.

substance added time of reaction / s

none 277
W 266
X 279
Y 78

(a) How would the student know when the reaction had finished?

..................................................................................................................................... [1]

(b) (i) State the effect of each substance on the speed (rate) of the reaction.

W ...............................................................................................................................

X ................................................................................................................................

Y .......................................................................................................................... [3]

(ii) Which substance, W, X or Y, is the best catalyst for this reaction?

.............................................................................................................................. [1]

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

..................................................................................................................................... [2]

[Total: 7]

© UCLES 2012 0620/62/M/J/12

7
For
5 A student investigated the temperature changes when two different solids, C and D, dissolved Examiner’s
in water. Use

Two experiments were carried out.

Experiment 1

Using a measuring cylinder, 25 cm3 of distilled water was poured into a polystyrene cup. The
initial temperature of the water was measured.
Solid C was added to the water, the timer started and the mixture stirred with a thermometer.
The temperature of the solution was measured every 30 seconds for three minutes.

(a) Use the thermometer diagrams in the table to record the temperatures.

thermometer
time / s temperature / °C
diagram

0 25

20
30

30 25

20
30

60 25

20
30

90 25

20
30

120 25

20
30

150 25

20
30

180 25

20
[2]

© UCLES 2012 0620/62/M/J/12 [Turn over

8
For
Experiment 2 Examiner’s
Use
The polystyrene cup was emptied and rinsed with water. Experiment 1 was repeated using
solid D instead of solid C. The temperature of the solution was measured every 30 seconds
for three minutes as before.

(b) Use the thermometer diagrams in the table to record the temperatures.

thermometer
time / s temperature / °C
diagram

0 20

15
25

30 20

15
25

60 20

15
25

90 20

15
25

120 20

15
25

150 20

15
25

180 20

[2]

© UCLES 2012 0620/62/M/J/12

9
For
(c) Plot the results for Experiments 1 and 2 on the grid and draw two smooth line graphs. Examiner’s
Clearly label your graphs. Use

22
temperature
of solution / °C

14
0 30 60 90 120 150 180

time / s
[6]

(d) (i) From your graph, deduce the temperature of the solution in Experiment 1 after
15 seconds.
Show clearly on the graph how you worked out your answer.

.........................................°C [2]

(ii) From your graph, deduce how long it takes for the initial temperature of the solution
in Experiment 2 to change by 1.5 °C.
Show clearly on the graph how you worked out your answer.

.........................................s [2]

© UCLES 2012 0620/62/M/J/12 [Turn over

10
For
(e) What type of change occurs when substance D dissolves in water? Examiner’s
Use
..................................................................................................................................... [1]

(f) Suggest the effect on the results if Experiment 1 was repeated using 50 cm3 of distilled
water.

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

..................................................................................................................................... [1]

(g) Predict the temperature of the solution in Experiment 2 after 1 hour. Explain your answer.

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

..................................................................................................................................... [2]

(h) When carrying out the experiments what would be the advantage of taking the temperature
readings every 15 seconds?

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

..................................................................................................................................... [2]

[Total: 20]

© UCLES 2012 0620/62/M/J/12

11
For
6 Two substances, E and F, were analysed. E was a solid compound and F was a solution of Examiner’s
ethanoic acid. Use
The tests on E and F, and some of the observations, are in the table. Complete the observations
in the table.
Do not write any conclusions in the table.

tests observations
tests on solid E

(a) Appearance of solid E. green powder

(b) Solid E was heated in a test-tube. black solid formed

The gas given off was tested. limewater turned milky

The solution was divided into two

equal portions in test-tubes.

(ii) Excess aqueous sodium hydroxide

was added to the first portion of the pale blue precipitate formed
solution.

(iii) Drops of aqueous ammonia were

added to the second portion of the pale blue precipitate formed
solution.

Excess aqueous ammonia was then precipitate dissolved to

added to the mixture. form a dark blue solution

tests on liquid F

(d) Appearance and smell of liquid F. appearance ...................................................

smell ........................................................ [2]

(e) pH indicator paper was used to measure
the pH of liquid F.
pH ............................................................ [1]

(f) Identify the gas given off in test (c)(i).

..................................................................................................................................... [1]

(g) Identify solid E.

..................................................................................................................................... [2]

[Total: 6]

© UCLES 2012 0620/62/M/J/12 [Turn over

12
For
7 Examiner’s
Fizzy drinks Use

The bubbles in fizzy drinks are bubbles of carbon dioxide. The carbon dioxide is dissolved in
the drink under pressure.
When a bottle of fizzy drink is opened the gas escapes and eventually the drink goes flat.
The gas is lost more quickly if the fizzy drink is heated.

(a) How could the acidity of the fizzy drink be checked?

..................................................................................................................................... [1]

(b) Plan an experiment to find the volume of gas in a bottle of fizzy drink.
You may use common laboratory apparatus.

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

..................................................................................................................................... [6]

[Total: 7]

© UCLES 2012 0620/62/M/J/12

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

CHEMISTRY 0620/12
Paper 1 Multiple Choice October/November 2012

45 Minutes
Additional Materials: Multiple Choice Answer Sheet
*5992676139*

Soft clean eraser

Soft pencil (type B or HB is recommended)

READ THESE INSTRUCTIONS FIRST

Write in soft pencil.

Read the instructions on the Answer Sheet very carefully.

This document consists of 15 printed pages and 1 blank page.

IB12 11_0620_12/FP
© UCLES 2012 [Turn over
2

1 What are the processes W, X, Y and Z in the following diagram?

W X
solid liquid gas
Y Z

W X Y Z

A condensing boiling freezing melting

B condensing freezing melting boiling
C melting boiling freezing condensing
D melting freezing condensing boiling

2 Part of the instructions in an experiment reads as follows.

Quickly add 50 cm3 of acid.

What is the best piece of apparatus to use?

A a burette
B a conical flask
C a measuring cylinder
D a pipette

3 A mixture of sulfur and iron filings needs to be separated. The solubilities of sulfur and iron filings
in water and carbon disulfide are shown in the table below.

solubility solubility in
in water carbon disulfide

sulfur
iron filings

What are possible methods of separating the sulfur and iron filings?

using using using

water carbon disulfide a magnet

A
B
C
D

© UCLES 2012 0620/12/O/N/12

4 Which row gives the number of electrons in the outer electron shell of fluorine and of neon?

19 20
9F 10 Ne

A 7 8
B 7 10
C 9 8
D 9 10

5 Which statements comparing the properties of electrons, neutrons and protons are correct?

neutrons and protons are only electrons and

both heavier than electrons neutrons are charged

A
B
C
D

6 The table shows the electronic structures of four atoms.

atom electronic structure

W 2,1
X 2,7
Y 2,8,4
Z 2,8,8

Which two atoms combine to form an ionic compound?

A W and X B W and Y C X and Y D X and Z

7 In the molecules CH4, HCl and H2O, which atoms use all of their outer shell electrons in bonding?

A C and Cl B C and H C Cl and H D H and O

© UCLES 2012 0620/12/O/N/12 [Turn over

8 A compound has the formula CH3CO2H.

How should the relative molecular mass, Mr, of this compound be calculated?

A 12 + 1 + 16
B 3(12 + 1) + 2(12 + 16) + 1

C (4 × 12) + (2 × 1) + 16

D (2 × 12) + (4 × 1) + (2 × 16)

9 The diagram shows an electrolysis experiment using metals X and Y as electrodes.

+ –

aqueous solution

X Y

One of the metals becomes coated with copper.

Which metal becomes coated and which aqueous solution is used?

aqueous
metal
solution

A X CrCl 3
B X CuCl 2
C Y CrCl 3
D Y CuCl 2

© UCLES 2012 0620/12/O/N/12

10 The diagram shows the electrolysis of concentrated aqueous sodium chloride.

positive negative
+ –
electrode carbon electrode
rods

concentrated
aqueous sodium
chloride

What is produced at each of the electrodes?

product at cathode product at anode

A hydrogen chlorine
B hydrogen oxygen
C sodium chlorine
D sodium oxygen

11 The diagrams show the difference in energies of the reactants and products in two types of
reaction.

diagram 1 diagram 2
heat taken in heat given out

products reactants

energy energy
reactants products

Which diagram and which type of energy change apply to a fuel burning in air?

diagram type of energy change

A 1 endothermic
B 1 exothermic
C 2 endothermic
D 2 exothermic

© UCLES 2012 0620/12/O/N/12 [Turn over

12 Which change is an oxidation?

A FeO to Fe2O3
B Fe2O3 to FeO
C H2O2 to H2O
D H2O to H2

13 The diagram shows a match.

By striking the match, a chemical reaction takes place.

Which statements about the chemical reaction are correct?

type of reaction reason

A endothermic because energy is used to strike the match

B endothermic because energy is given out as the match burns
C exothermic because energy is used to strike the match
D exothermic because energy is given out as the match burns

14 Separate samples of anhydrous and hydrated copper(II) sulfate are heated.

anhydrous hydrated
copper(II) sulfate copper(II) sulfate
heat heat

Which shows the correct colour changes?

anhydrous copper(II) sulfate hydrated copper(II) sulfate

A blue to white white to blue

B no change blue to white
C white to blue blue to white
D white to blue no change

© UCLES 2012 0620/12/O/N/12

15 Element X forms an acidic, covalent oxide.

Which row shows how many electrons there could be in the outer shell of an atom of X?

1 2 6 7

A
B
C
D

16 Which change does not increase the speed of reaction between zinc and hydrochloric acid?

A adding a catalyst
B decreasing the particle size of the zinc
C decreasing the temperature
D using more concentrated acid

17 Barium hydroxide is an alkali. It reacts with hydrochloric acid.

How does the pH of the hydrochloric acid change as an excess of aqueous barium hydroxide is
added?

A The pH decreases from 14 and becomes constant at 7.

B The pH decreases from 14 to about 1.
C The pH increases from 1 and becomes constant at 7.
D The pH increases from 1 to about 14.

18 Which of these pairs of aqueous ions both react with dilute sulfuric acid to give a visible result?

A Ba2+ and Cl −

B Ba2+ and CO32−

C NH4+ and Cl −

D NH4+ and CO32−

19 A compound is a salt if it

A can neutralise an acid.

B contains more than one element.
C dissolves in water.
D is formed when an acid reacts with a base.

© UCLES 2012 0620/12/O/N/12 [Turn over

20 The table gives information about four elements.

Which element is a transition metal?

electrical
colour colour
conductivity
of element of oxide
of element

A black high colourless

B colourless low white
C grey high red
D yellow low colourless

21 The diagram shows an outline of the Periodic Table.

U V W X Y

Which of the elements U, V, W, X and Y would react together in the ratio of 1 : 1?

A U and X B U and Y C V and Y D W and X

22 The element rubidium, Rb, is immediately below potassium in the Periodic Table.

It reacts with bromine to form the compound rubidium bromide.

Which descriptions of this compound are correct?

type of bond formula colour

A covalent RbBr brown

B covalent RbBr2 white
C ionic RbBr white
D ionic RbBr2 brown

© UCLES 2012 0620/12/O/N/12

23 Brass is used in electrical equipment.

It contains two ……1…… elements. Together they form ……2…… .

Which words correctly complete gaps 1 and 2?

1 2

A metallic a covalent compound

B metallic an alloy
C non-metallic a covalent compound
D non-metallic an alloy

24 Why are weather balloons filled with helium rather than hydrogen?

A Helium is found in air.

B Helium is less dense than hydrogen.
C Helium is more dense than hydrogen.
D Helium is unreactive.

25 Some properties of aluminium are listed.

1 It has mechanical strength.

2 It conducts heat.
3 It is resistant to corrosion.
4 It has a low density.

Which properties make aluminium useful for making the bodies of aircraft?

A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

© UCLES 2012 0620/12/O/N/12 [Turn over

26 Pieces of copper, iron, magnesium and zinc are added to separate test-tubes containing dilute
hydrochloric acid.

Which test-tube contains iron and dilute hydrochloric acid?

A B C D

27 The Basic Oxygen Process converts iron into steel.

In step 1, oxygen is blown into impure molten iron.

In step 2, oxides are removed by reaction with calcium oxide.

oxygen

waste
gases

molten iron
and
calcium oxide

Which chemical reaction takes place in step 1 and which type of oxides are removed in step 2?

chemical reaction type of oxides removed

in step 1 in step 2

A carbon is converted to carbon dioxide acidic

B carbon is converted to carbon dioxide basic
C iron is converted to iron(III) oxide acidic
D iron is converted to iron(III) oxide basic

© UCLES 2012 0620/12/O/N/12

28 What is the correct order of abundance of the gases in the air?

A nitrogen → oxygen → argon → carbon dioxide

B nitrogen → oxygen → carbon dioxide → argon

C oxygen → nitrogen → argon → carbon dioxide

D oxygen → nitrogen → carbon dioxide → argon

29 Which processes are used in the treatment of water?

A filtration and chlorination

B filtration and reduction
C neutralisation and chlorination
D neutralisation and reduction

30 A factory burns coal with a high sulfur content.

Which pollutant is most likely to lead to the death of trees?

A carbon dioxide
B carbon monoxide
C lead compounds
D sulfur dioxide

31 The diagram shows an experiment to investigate how paint affects the rusting of iron.

P Q
iron painted iron

air

water

What happens to the water level in tubes P and Q?

tube P tube Q

A falls rises
B no change rises
C rises falls
D rises no change

© UCLES 2012 0620/12/O/N/12 [Turn over

32 Carbon dioxide is produced when dilute hydrochloric acid reacts with

A calcium sulfate.
B carbon.

C copper(II) carbonate.
D limewater.

33 The diagram shows two substances, X and Y, being heated together.

damp Universal Indicator

paper

substances X and Y

heat

The Universal Indicator paper turns blue during the experiment.

What are substances X and Y?

A ammonium nitrate and hydrochloric acid

B ammonium nitrate and sodium hydroxide
C sodium carbonate and hydrochloric acid
D sodium carbonate and sodium hydroxide

© UCLES 2012 0620/12/O/N/12

34 A student is asked to draw a diagram showing the uses of limestone.

making
making lime
cement

1 2

limestone

added, with hematite,

to a blast furnace

Which numbered lines show a correct use of limestone?

A 1 and 2 only
B 1 and 3 only
C 2 and 3 only
D 1, 2 and 3

35 Which properties of the different compounds in petroleum enable its separation into fractions?

1 boiling point
2 chain length
3 chemical reactivity
4 solubility in water

A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

36 Which structure is correctly named?

A B C D

H H H H H H H H

H C C C O H H C C H H C C O H C C C H

H H O H H H H H H H
ethanoic acid ethene ethanol propane

37 Alkenes have the general formula CnH2n.

Which of the following is an alkene?

A CH2 B CH4 C C3H6 D C6H6

© UCLES 2012 0620/12/O/N/12 [Turn over

38 A hydrocarbon X is cracked to make Y and hydrogen.

Compound Z is formed by the addition polymerisation of Y.

To which homologous series do X, Y and Z belong?

alkane alkene

A X, Y and Z –
B X and Y Z
C X and Z Y
D Y and Z X

39 Bitumen is a substance obtained from the fractional distillation of petroleum.

Which row describes its boiling point and the size of its molecules?

boiling point size of molecules

A high large
B high small
C low large
D low small

40 Which row is correct for ethanol?

made by
burns
fermentation

A
B
C
D

© UCLES 2012 0620/12/O/N/12

BLANK PAGE

© UCLES 2012 0620/12/O/N/12

7 9 11 12 14 16 19 20
Li Be B C N O F Ne
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
3 4 5 6 7 8 9 10

23 24 27 28 31 32 35.5 40
Na Mg Al Si P S Cl Ar
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
11 12 13 14 15 16 17 18

39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton

publisher will be pleased to make amends at the earliest possible opportunity.

19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
16

85 88 89 91 93 96 101 103 106 108 112 115 119 122 128 127 131

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Tin Antimony Tellurium Xenon

0620/12/O/N/12
Indium Iodine
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

133 137 139 178 181 184 186 190 192 195 197 201 204 207 209

226 227
Fr Ra Ac

Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
Francium Radium Actinium
87 88 89

The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).

University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of
Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every
reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education
*2998687209*

CHEMISTRY 0620/22
Paper 2 October/November 2012
1 hour 15 minutes
Candidates answer on the Question Paper.
No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Answer all questions.

A copy of the Periodic Table is printed on page 16.

At the end of the examination, fasten all your work securely together. For Examiner’s Use
The number of marks is given in brackets [ ] at the end of each question or part
question. 1

Total

This document consists of 14 printed pages and 2 blank pages.

IB12 11_0620_22/2RP
© UCLES 2012 [Turn over
2
For
1 The diagram shows the structures of five elements, A, B, C, D and E. Examiner’s
Use
A B C D E
C
P
C P
C
C
Cl Cl P He He
Cu Cu Cu Cu C P
P
C
C Cl P
P
Cu Cu Cu Cu C C
C
Cl P He He
C C P
C C
Cu Cu Cu Cu C C C Cl P
C
C C
C C
C
Cl P He He
C C C
C C P
C
C

(a) Answer these questions using the letters A, B, C, D or E.

Each element can be used once, more than once or not at all.

Which one of these elements

(i) is in Group V of the Periodic Table, ..................................................................... [1]

(ii) is used to fill weather balloons, ............................................................................ [1]

(iii) is a diatomic gas at room temperature, ............................................................... [1]

(iv) conducts electricity, .............................................................................................. [1]

(v) is a transition element? ........................................................................................ [1]

(b) Which two of the elements A, B, C, D or E are simple molecules?

............................................................. and ............................................................. [2]

covalent giant ionic

metallic simple atomic simple molecular

............................................................. and ............................................................. [2]

(d) What do you understand by the term element ?

..................................................................................................................................... [1]

[Total: 10]

© UCLES 2012 0620/22/O/N/12

3
For
2 Ammonia, NH3, is an alkaline gas. Examiner’s
Use
(a) Describe a test for ammonia.

test ....................................................................................................................................

result ........................................................................................................................... [2]

(b) What is the pH of an aqueous solution of ammonia?

Put a ring around the correct answer.

pH 1 pH 3 pH 5 pH 7 pH 9
[1]

(c) Ammonia reacts with hydrochloric acid.

(i) Complete the symbol equation for this reaction.

NH3 + HCl → ..............

[1]

(ii) Hydrochloric acid can be made by dissolving hydrogen chloride, HCl, in water.
Draw a diagram to show the arrangement of electrons in hydrogen chloride.
Show only the outer electrons.

Show a hydrogen electron as ●

Show a chlorine electron as x

[2]

© UCLES 2012 0620/22/O/N/12 [Turn over

4
For
(d) Aqueous ammonia reacts with sulfuric acid to form a solution of ammonium sulfate. Examiner’s
Use
2NH3(aq) + H2SO4 (aq) → (NH4)2SO4 (aq)

(i) Ammonium sulfate is a colourless salt. Describe how you could use a titration method
to make a colourless solution of ammonium sulfate.

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

.............................................................................................................................. [4]

(ii) How can crystals of ammonium sulfate be obtained from a solution of ammonium
sulfate?

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

.............................................................................................................................. [1]

[Total: 11]

© UCLES 2012 0620/22/O/N/12

5
For
3 The table below shows the properties of some halogens. Examiner’s
Use

state at room melting point

halogen colour
temperature / °C

fluorine yellow –220

chlorine light green gas
bromine brownish-red liquid –7
iodine grey-black solid +114

(a) (i) What is the trend in the colour of the halogens down the Group?

.............................................................................................................................. [1]

(ii) Predict the state of fluorine at room temperature.

.............................................................................................................................. [1]

(iii) Predict the melting point of chlorine.

.............................................................................................................................. [1]

(b) The reactivity of three different halogens was compared by reacting them with solutions
of sodium halides.
The results are shown in the table below.

reaction mixture observations

astatine + sodium iodide colour of reaction mixture remains unchanged

bromine + sodium iodide mixture turns dark brown
chlorine + sodium bromide mixture turns brownish-red

(i) Use the results in the table to suggest the order of reactivity of astatine, bromine,
chlorine and iodine.

most reactive least reactive

[2]

(ii) Predict whether bromine will react with sodium chloride solution.
Explain your answer.

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

.............................................................................................................................. [1]

© UCLES 2012 0620/22/O/N/12 [Turn over

6
For
(c) Chlorine reacts with excess cold dilute sodium hydroxide. The products of the reaction Examiner’s
are sodium chloride, sodium chlorate(I) and water. Use
The formula of sodium chlorate(I) is NaCl O.

Complete the equation for this reaction.

Cl 2 + ......NaOH → NaCl + NaCl O + ..........

[2]

(d) (i) Explain why chlorine is used in water purification.

.............................................................................................................................. [1]

(ii) Impure water contains particles of minerals and remains of dead plants and animals.
One stage in water purification is the removal of these particles by filtration.
The diagram below shows a water filter.

small particles
of sand
water in

Explain how this water filter works.

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

.............................................................................................................................. [2]

[Total: 11]

© UCLES 2012 0620/22/O/N/12

7
For
4 The process of distillation is used in an oil refinery to separate petroleum into different Examiner’s
fractions. Use

(a) What do you understand by the term petroleum fraction ?

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

..................................................................................................................................... [2]

(b) Some petroleum fractions are more useful than others. There is a greater demand for
these fractions.
The diagram shows the demand from customers and the ability of an oil refinery to
supply these fractions by fractional distillation alone.

30 supply from refinery

percentage

20 demand

0
refinery gas

gasoline

kerosene

diesel

fuel oil

and bitumen
lubricating oil

(i) State the name of two fractions for which demand is greater than supply.

.............................................................................................................................. [2]

(ii) State one use for each of the following fractions.

refinery gas ................................................................................................................

bitumen ................................................................................................................ [2]

(c) More gasoline can be made by cracking long-chain hydrocarbons.

State the conditions needed for cracking.

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

..................................................................................................................................... [2]

© UCLES 2012 0620/22/O/N/12 [Turn over

8
For
(d) Dodecane, C12H26, can be cracked to form smaller hydrocarbons. Examiner’s
Use
(i) What do you understand by the term hydrocarbon ?

.............................................................................................................................. [1]

(ii) Complete the equation for the cracking of dodecane.

C12H26 → C8H18 + .............

[1]

(e) Ethene, C2H4, can be formed by cracking.

(i) Draw the full structure of ethene showing all atoms and bonds.

[1]

(ii) Poly(ethene) can be made from ethene.

Complete the following sentences using words from the list below.

addition atoms condensation dimers

monomers polymers subtraction

The small ethene molecules which join together to form poly(ethene) are called
ethene ............................ . The process of joining the ethene molecules together is
an example of an ............................ reaction. The long-chain molecules which are
formed are called ............................ . [3]

[Total: 14]

© UCLES 2012 0620/22/O/N/12

9
For
5 Aluminium is in Group III of the Periodic Table. Iron is a transition element. Examiner’s
Use
(a) Both aluminium and iron have high melting points and boiling points.
State two differences in the physical properties of aluminium and iron.

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

..................................................................................................................................... [2]

(b) State one use of aluminium.

..................................................................................................................................... [1]

(c) Sodium hydroxide is used to test for aluminium ions.

Describe what happens when you add a solution of sodium hydroxide to a solution of
aluminium ions until the sodium hydroxide is in excess.

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

..................................................................................................................................... [3]

[Total: 6]

© UCLES 2012 0620/22/O/N/12 [Turn over

10
For
6 The diagram below shows a kiln used for manufacturing lime. Examiner’s
Use
waste gases

mixture of
calcium carbonate
and coke

air blown in

lime
removed

The reaction taking place in the kiln is

calcium carbonate → calcium oxide + carbon dioxide

(lime)

(a) (i) State the name of a rock which is largely calcium carbonate.

.............................................................................................................................. [1]

(ii) Explain why, at the end of the reaction, there is only lime left in the lime kiln.

.............................................................................................................................. [1]

(b) (i) Coke is mainly carbon.

Combustion of coke provides the heat for the reaction in the lime kiln.
Write a symbol equation for the complete combustion of carbon in oxygen.

.............................................................................................................................. [2]

(ii) Complete these sentences using words from the list below.

air dioxide harmless hydrogenated

limited monoxide poisonous water

When carbon burns in a .............................. supply of .............................., carbon

.............................. is formed. This is a colourless gas which has no smell and is
.............................. . [4]

© UCLES 2012 0620/22/O/N/12

11
For
(c) Calcium carbonate reacts with hydrochloric acid to form carbon dioxide. Examiner’s
Complete the word equation for this reaction. Use

calcium hydrochloric ............................. carbon

+ → + ............................. +
carbonate acid ............................. dioxide
[2]

(d) The speed of reaction of calcium carbonate with hydrochloric acid can be found using the
apparatus shown below.

cotton wool

small pieces of hydrochloric acid

calcium carbonate

top pan balance

(i) Suggest how this apparatus can be used to find the speed of this reaction.

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

.............................................................................................................................. [2]

(ii) State how the speed of this reaction changes when

the concentration of acid is increased, ......................................................................

larger pieces of calcium carbonate are used, ............................................................

the temperature is increased. .............................................................................. [3]

[Total: 15]

© UCLES 2012 0620/22/O/N/12 [Turn over

12
For
7 The structures of iodine and potassium iodide are shown below. Examiner’s
Use
I I I I
K+ I– K+ I–
I I I I
I I I I I– K+ I– K+
I I I I K+ I– K+ I–
I I I I I– K+ I– K+
I I I I

iodine potassium iodide

(a) Iodine is a solid at room temperature. Its melting point is +114 °C.

(i) Describe what happens to the arrangement and movement of iodine molecules
when iodine is gradually heated from 20 °C to 120 °C.

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

.............................................................................................................................. [4]

(ii) Calculate the relative molecular mass of iodine.

.............................................................................................................................. [1]

(b) (i) What type of bonding is present in potassium iodide?

.............................................................................................................................. [1]

(ii) Write the simplest formula for potassium iodide.

.............................................................................................................................. [1]

© UCLES 2012 0620/22/O/N/12

13
For
(c) Complete the table below to show the solubility in water and electrical conductivity of Examiner’s
solid iodine and solid potassium iodide. Use

electrical conductivity
substance solubility in water
of solid

iodine

potassium iodide

[4]

(d) Predict the product formed at each electrode when molten potassium iodide is
electrolysed.

at the positive electrode ....................................................................................................

at the negative electrode ............................................................................................ [2]

[Total: 13]

© UCLES 2012 0620/22/O/N/12 [Turn over

BLANK PAGE

© UCLES 2012 0620/22/O/N/12

BLANK PAGE

© UCLES 2012 0620/22/O/N/12

7 9 11 12 14 16 19 20
Li Be B C N O F Ne
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
3 4 5 6 7 8 9 10

23 24 27 28 31 32 35.5 40
Na Mg Al Si P S Cl Ar
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
11 12 13 14 15 16 17 18

39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

publisher will be pleased to make amends at the earliest possible opportunity.

85 88 89 91 93 96 101 103 106 108 112 115 119 122 128 127 131

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

0620/22/O/N/12
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

133 137 139 178 181 184 186 190 192 195 197 201 204 207 209

226 227
Fr Ra Ac

Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
Francium Radium Actinium
87 88 89

The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).

University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of
reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included the
Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education
*1580108680*

CHEMISTRY 0620/32
Paper 3 (Extended) October/November 2012
1 hour 15 minutes
Candidates answer on the Question Paper.
No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Answer all questions.

A copy of the Periodic Table is printed on page 16.

At the end of the examination, fasten all your work securely together. For Examiner’s Use
The number of marks is given in brackets [ ] at the end of each question or part
question. 1

Total

This document consists of 13 printed pages and 3 blank pages.

IB12 11_0620_32/2RP
© UCLES 2012 [Turn over
2
For
1 This question is concerned with the elements in Period 5, Rb to Xe. Examiner’s
Use
(a) The electron distributions of some of these elements are given in the following list.

element A 2 + 8 + 18 + 8 + 2
element B 2 + 8 + 18 + 18 + 8
element C 2 + 8 + 18 + 18 + 5
element D 2 + 8 + 18 + 18 + 6
element E 2 + 8 + 18 + 18 + 4
element F 2 + 8 + 18 + 18 + 7

(i) Identify element C. ............................................................................................... [1]

(ii) Which element in the list does not form any compounds?

.............................................................................................................................. [1]

(iii) Which element in the list forms a chloride of the type XCl 2?

.............................................................................................................................. [1]

(iv) Which two elements would react together to form a compound of the type XY4?

.............................................................................................................................. [1]

(v) Which element in the list would react with cold water to form an alkaline solution and
hydrogen?

.............................................................................................................................. [1]

(b) Predict two differences in physical properties and two differences in chemical properties
between rubidium and the transition metal niobium.

physical .............................................................................................................................

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

chemical ...........................................................................................................................

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

..................................................................................................................................... [4]

[Total: 9]

© UCLES 2012 0620/32/O/N/12

3
For
2 The diagram shows a heating curve for a sample of compound X. Examiner’s
Use

D
80 E

temperature / °C

B
15 C
A
time

(a) Is X a solid, a liquid or a gas at room temperature, 20 °C?

..................................................................................................................................... [1]

(b) Write an equation for the equilibrium which exists in region BC.

..................................................................................................................................... [2]

(c) Name the change of state which occurs in region DE.

..................................................................................................................................... [1]

(d) Explain how the curve shows that a pure sample of compound X was used.

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

..................................................................................................................................... [2]

[Total: 6]

© UCLES 2012 0620/32/O/N/12 [Turn over

4
For
3 Many organic compounds which contain a halogen have chloro, bromo or iodo in their name. Examiner’s
Use
(a) The following diagram shows the structure of 1-chloropropane.

H H H

H C C C Cl

H H H

(i) Draw the structure of an isomer of this compound.

[1]

(ii) Describe how 1-chloropropane could be made from propane.

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

.............................................................................................................................. [2]

(iii) Suggest an explanation why the method you have described in (ii) does not produce
a pure sample of 1-chloropropane.

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

.............................................................................................................................. [2]

(b) Organic halides react with water to form an alcohol and a halide ion.

CH3–CH2–I + H2O → CH3–CH2–OH + I –

(i) Describe how you could show that the reaction mixture contained an iodide ion.

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

.............................................................................................................................. [2]

(ii) Name the alcohol formed when 1-chloropropane reacts with water.

.............................................................................................................................. [1]

© UCLES 2012 0620/32/O/N/12

5
For
(c) The speed (rate) of reaction between an organic halide and water can be measured by Examiner’s
the following method. Use

A mixture of 10 cm3 of aqueous silver nitrate and 10 cm3 of ethanol is warmed to 60 °C.
Drops of the organic halide are added and the time taken for a precipitate to form is
measured.

Silver ions react with the halide ions to form a precipitate of the silver halide.

Ag+(aq) + X–(aq) → AgX(s)

Typical results for four experiments, A, B, C and D, are given in the table.

experiment organic halide number of drops time / min

A bromobutane 4 6
B bromobutane 8 3
C chlorobutane 4 80
D iodobutane 4 0.1

(i) Explain why it takes longer to produce a precipitate in experiment A than in B.

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

.............................................................................................................................. [2]

(ii) How does the order of reactivity of the organic halides compare with the order of
reactivity of the halogens?

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

.............................................................................................................................. [2]

(iii) Explain why the time taken to produce a precipitate would increase if the experiments
were repeated at 50 °C.

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

.............................................................................................................................. [3]

[Total: 15]

© UCLES 2012 0620/32/O/N/12 [Turn over

6
For
4 Iron is extracted from its ore, hematite, in the blast furnace. Examiner’s
Use
waste gases

raw materials:
coke, C
limestone, CaCO3
firebrick lining hematite, Fe2O3

air

slag

molten iron

(a) The temperature inside the blast furnace can rise to 2000 °C.
Write an equation for the exothermic reaction which causes this high temperature.

..................................................................................................................................... [1]

(b) Carbon monoxide is formed in the blast furnace. This reduces the ore hematite, Fe2O3,
to iron.

(i) Explain how carbon monoxide is formed in the blast furnace.

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

.............................................................................................................................. [2]

(ii) Write an equation for the reduction of hematite by carbon monoxide.

.............................................................................................................................. [2]

(c) Explain why it is necessary to add limestone, calcium carbonate, to the blast furnace.
Include an equation in your explanation.

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

..................................................................................................................................... [3]

© UCLES 2012 0620/32/O/N/12

7
For
(d) Most of the iron from the blast furnace is converted into mild steel. A method of preventing Examiner’s
the steel from rusting is coating it with zinc. Use

(i) What is the name of this method of rust prevention?

.............................................................................................................................. [1]

(ii) Explain, using the idea of electron transfer, why zinc-coated steel does not rust even
when the coating is scratched and the steel is in contact with oxygen and water.

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

.............................................................................................................................. [3]

[Total: 12]

© UCLES 2012 0620/32/O/N/12 [Turn over

8
For
5 The food additive E220 is sulfur dioxide. It is a preservative for a variety of foods and drinks. Examiner’s
Use
(a) State two other uses of sulfur dioxide.

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

..................................................................................................................................... [2]

(b) How is sulfur dioxide manufactured?

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

..................................................................................................................................... [2]

(c) Sulfur dioxide is a reductant (reducing agent). Describe what you would see when
aqueous sulfur dioxide is added to acidified potassium manganate(VII).

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

..................................................................................................................................... [2]

(d) Sulfur dioxide can also be made by the reaction between a sulfite and an acid.

Na2SO3 + 2HCl → 2NaCl + SO2 + H2O

Excess hydrochloric acid was added to 3.15 g of sodium sulfite. Calculate the maximum
volume, measured at r.t.p., of sulfur dioxide which could be formed.
The mass of one mole of Na2SO3 is 126 g.

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

..................................................................................................................................... [3]

[Total: 9]

© UCLES 2012 0620/32/O/N/12

9
For
6 During electrolysis, ions move in the electrolyte and electrons move in the external circuit. Examiner’s
Reactions occur at the electrodes. Use

(a) The diagram shows the electrolysis of molten lithium iodide.

+ –

external circuit

electrode electrode

molten lithium iodide

heat

(i) Draw an arrow on the diagram to show the direction of the electron flow in the
external circuit. [1]

(ii) Electrons are supplied to the external circuit. How and where is this done?

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

.............................................................................................................................. [2]

(iii) Explain why solid lithium iodide does not conduct electricity but when molten it is a
good conductor.

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

.............................................................................................................................. [1]

(b) The results of experiments on electrolysis are shown in the following table. Complete the
table. The first line has been done as an example.

product at product at change to

electrolyte electrodes
cathode anode electrolyte

molten lithium iodide carbon lithium iodine used up

aqueous copper(II) sulfate platinum oxygen

concentrated aqueous
carbon chlorine
potassium chloride

[4]

© UCLES 2012 0620/32/O/N/12 [Turn over

10
For
(c) The diagram below shows the electrolysis of dilute sulfuric acid. Hydrogen is formed at Examiner’s
the negative electrode (cathode) and oxygen at the positive electrode (anode) and the Use
concentration of sulfuric acid increases.

+ –

carbon anode carbon cathode

dilute sulfuric acid

bubbles of bubbles of
oxygen gas hydrogen gas

The ions present in the dilute acid are H+(aq), OH–(aq) and SO42–(aq).

(i) Write an equation for the reaction at the negative electrode (cathode).

.............................................................................................................................. [2]

(ii) Complete the equation for the reaction at the positive electrode (anode).

4OH–(aq) → O2(g) + .....H2O(l) + ....... [1]

(iii) Suggest an explanation of why the concentration of the sulfuric acid increases.

.............................................................................................................................. [1]

(d) In the apparatus used in (c), the power supply is removed and immediately replaced by
a voltmeter.

voltmeter
V

carbon anode carbon cathode

dilute sulfuric acid

bubbles of bubbles of
oxygen gas hydrogen gas

A reading on the voltmeter shows that electrical energy is being produced. Suggest an
explanation for how this energy is produced.

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

..................................................................................................................................... [3]

[Total: 15]

© UCLES 2012 0620/32/O/N/12

11
For
7 The alcohols form a homologous series. The first member of this series is methanol, CH3OH. Examiner’s
Use
(a) (i) Give the general formula of the alcohols.

.............................................................................................................................. [1]

(ii) The mass of one mole of an alcohol is 116 g. What is its formula?
Show your reasoning.

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

.............................................................................................................................. [2]

(iii) Draw a diagram showing the arrangement of the outer (valency) electrons in one
molecule of methanol.

Use x to represent an electron from a carbon atom.

Use o to represent an electron from a hydrogen atom.
Use ● to represent an electron from an oxygen atom.

[3]

(b) Methanol is manufactured using the following method.

CH4(g) + H2O(g) → CO(g) + 3H2(g) reaction 1

CO(g) + 2H2(g) CH3OH(g) reaction 2

The conditions for reaction 2 are:

pressure 100 atmospheres

catalyst a mixture of copper, zinc oxide and aluminium oxide
temperature 250 °C

The forward reaction is exothermic.

(i) Why is high pressure used in reaction 2?

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

.............................................................................................................................. [2]

© UCLES 2012 0620/32/O/N/12 [Turn over

12
For
(ii) Explain why using a catalyst at 250 °C is preferred to using a higher temperature of Examiner’s
350 °C and no catalyst. Use

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

.............................................................................................................................. [3]

(c) Methanol is oxidised by atmospheric oxygen. This reaction is catalysed by platinum.

(i) The products of this reaction include a carboxylic acid. Give its name and structural
formula.

name .......................................................

structural formula showing all bonds

[2]

(ii) Deduce the name of the ester formed by the reaction of methanol with the carboxylic
acid named in (i).

.............................................................................................................................. [1]

[Total: 14]

© UCLES 2012 0620/32/O/N/12

BLANK PAGE

© UCLES 2012 0620/32/O/N/12

BLANK PAGE

© UCLES 2012 0620/32/O/N/12

BLANK PAGE

© UCLES 2012 0620/32/O/N/12

7 9 11 12 14 16 19 20
Li Be B C N O F Ne
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
3 4 5 6 7 8 9 10

23 24 27 28 31 32 35.5 40
Na Mg Al Si P S Cl Ar
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
11 12 13 14 15 16 17 18

39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

publisher will be pleased to make amends at the earliest possible opportunity.

85 88 89 91 93 96 101 103 106 108 112 115 119 122 128 127 131

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

0620/32/O/N/12
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

133 137 139 178 181 184 186 190 192 195 197 201 204 207 209

226 227
Fr Ra Ac

Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
Francium Radium Actinium
87 88 89

The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).

University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of
reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included the
Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education
*9139900259*

CHEMISTRY 0620/52
Paper 5 Practical Test October/November 2012
1 hour 15 minutes
Candidates answer on the Question Paper.
Additional Materials: As listed in the Confidential Instructions

READ THESE INSTRUCTIONS FIRST

Answer all questions.

Practical notes are provided on page 8.

At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question or part question.

For Examiner’s Use

Total

This document consists of 7 printed pages and 1 blank page.

IB12 11_0620_52/FP
© UCLES 2012 [Turn over
2
For
1 You are going to investigate the speed of reaction when iodine is produced by the reaction Examiner’s
of solution L with potassium iodide at different temperatures. Use

Read all the instructions below carefully before starting the experiments.

Instructions
You are going to carry out five experiments.

(a) Experiment 1

Fill the burette with the aqueous solution L provided to the 0.0 cm3 mark.
Add 10 cm3 of solution L from the burette into a boiling tube. Record the initial temperature
of the solution in the table.

Use a measuring cylinder to pour 5 cm3 of the aqueous potassium iodide and 3 cm3 of
aqueous sodium thiosulfate provided into a second boiling tube. Add 2 cm3 of the starch
solution provided to this boiling tube and shake the mixture.

Add the mixture in the second boiling tube to the solution L in the first boiling tube, shake
the mixture and start the clock. These chemicals react to form iodine which reacts with
starch. When a blue colour first appears stop the clock and record the time in the table.
Measure and record the final temperature of the mixture in the table.

(b) Experiment 2

Discard the contents of the boiling tube and rinse both boiling tubes with distilled water.

Use a measuring cylinder to pour 5 cm3 of aqueous potassium iodide and 3 cm3 of
aqueous sodium thiosulfate into the first boiling tube. Add 2 cm3 of the starch solution
and shake the mixture.

Add 10 cm3 of solution L from the burette into the second boiling tube. Heat solution L
to about 40 °C stirring with a thermometer. Record the temperature of solution L in the
table.

Add the mixture in the first boiling tube to the solution L, shake the mixture and start the
clock. When a blue colour first appears, stop the clock and record the time in the table.
Measure and record the final temperature of the mixture in the table.

Repeat Experiment 2, heating solution L to about 50 °C.

(d) Experiment 4

Repeat Experiment 2, heating solution L to about 60 °C.

(e) Experiment 5

Repeat Experiment 2, heating solution L to about 70 °C.

© UCLES 2012 0620/52/O/N/12

3
For
(f) Complete the table of results. Examiner’s
Use

temperature of final temperature average time for blue colour

experiment
solution L / °C of mixture / °C temperature / °C to appear / s

1
2
3
4
5

[5]

(g) Plot the results on the grid below and draw a smooth line graph.

300

250

200
time / s

150

100

0
0 10 20 30 40 50 60 70 80
average temperature / °C
[5]

© UCLES 2012 0620/52/O/N/12 [Turn over

4
For
(h) From your graph, work out the time taken for the blue colour to first appear if solution L Examiner’s
was heated to 80 °C. The final temperature of the reaction mixture was 64 °C. Use
Show on the grid how you obtained your answer.

..................................................................................................................................... [3]

(i) Suggest the purpose of the starch solution in the experiments.

..................................................................................................................................... [1]

(j) (i) In which experiment was the reaction speed fastest?

.............................................................................................................................. [1]

(ii) Explain, using ideas about particles, why this experiment was the fastest.

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

.............................................................................................................................. [2]

(k) Predict the effect on the time and speed of the reaction in Experiment 5 if it was repeated
using a less concentrated solution of L.

time ...................................................................................................................................

speed .......................................................................................................................... [2]

(l) Why was a burette used to measure solution L instead of a measuring cylinder?

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

..................................................................................................................................... [1]

[Total: 20]

© UCLES 2012 0620/52/O/N/12

5
For
2 You are provided with a mixture of two solids, M and N. Examiner’s
Solid M is water-soluble and solid N is insoluble. Use
Carry out the following tests on the mixture, recording all of your observations in the table.
Conclusions must not be written in the table.

tests observations

Add about 15 cm3 of distilled water to the

mixture in a boiling tube.
Stopper and shake the boiling tube for one
minute. Filter the contents of the boiling tube,
keeping the filtrate and residue for the following
tests.

tests on the filtrate

Divide the filtrate into five portions in five

test-tubes.

(a) Use pH indicator paper to test the pH of

the filtrate. ................................................................ [1]

(b) (i) To the second portion of the filtrate,

add drops of aqueous sodium
hydroxide and shake the mixture. ......................................................................

Now add excess aqueous sodium

hydroxide to the test-tube. ................................................................ [3]

(ii) To the third portion of the filtrate,

add drops of aqueous ammonia and
shake the mixture. ......................................................................

Now add excess aqueous ammonia

to the test-tube. ................................................................ [3]

(c) To the fourth portion of the filtrate, add

about 1 cm3 of dilute nitric acid followed by
silver nitrate solution. ................................................................ [1]

(d) To the fifth portion of the filtrate, add

about 1 cm3 of dilute nitric acid followed by
barium nitrate solution. ................................................................ [2]

© UCLES 2012 0620/52/O/N/12 [Turn over

6
For
tests observations Examiner’s
Use

tests on the residue

Use a spatula to transfer some of the residue

into two test-tubes.

(e) To the first sample of the residue, add

about 3 cm3 of dilute hydrochloric acid. Boil
the mixture for about two minutes and test ......................................................................
the gas given off with damp blue litmus
paper. ................................................................ [2]

(f) To the second sample of the residue,

add about 3 cm3 of aqueous hydrogen
peroxide. ......................................................................

Test the gas given off. ................................................................ [3]

(g) What conclusions can you draw about solid M?

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

..................................................................................................................................... [2]

(h) Identify the gas given off in test (f).

..................................................................................................................................... [1]

(i) What conclusions can you draw about solid N?

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

..................................................................................................................................... [2]

[Total: 20]

© UCLES 2012 0620/52/O/N/12

BLANK PAGE

© UCLES 2012 0620/52/O/N/12

NOTES FOR USE IN QUALITATIVE ANALYSIS

Test for anions

anion test test result

Test for aqueous cations

cation effect of aqueous sodium hydroxide effect of aqueous ammonia

Test for gases

gas test and test results

© UCLES 2012 0620/52/O/N/12

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

CHEMISTRY 0620/52
Paper 5 Practical Test October/November 2012

CONFIDENTIAL INSTRUCTIONS
Great care should be taken to ensure that any confidential information given does not reach the
*2648721992*

candidates either directly or indirectly.

READ THESE INSTRUCTIONS FIRST

More material may be issued if required, without penalty, but this should not be necessary. Safety spectacles
may be provided if considered necessary.

In accordance with COSHH (Control of Substances Hazardous to Health) Regulations, operative in the UK, a
hazard appraisal of the examination has been carried out.

Attention is drawn, in particular, to certain materials used in the examination. The following codes are used
where relevant.

C = corrosive substance F = highly flammable substance

H = harmful or irritating substance O = oxidising substance

N = harmful to the environment T = toxic substance

Hazard data sheets should be available from your suppliers.

This document consists of 5 printed pages and 3 blank pages.

IB12 11_0620_52CI/FP
© UCLES 2012 [Turn over
2

For Question 1

Each candidate will require

(a) three 10 cm3 measuring cylinders

(b) one 50 cm3 burette

(c) two boiling tubes

[H][O] (d) 100 cm3 of aqueous potassium peroxodisulfate, K2S2O8, of concentration 0.02 mol / dm3,
(5.4 g / dm3), labelled solution L

(e) 50 cm3 of aqueous potassium iodide, KI, of concentration 0.5 mol / dm3, (83 g / dm3), labelled
aqueous potassium iodide.
This solution should be freshly prepared.

(f) 50 cm3 of aqueous sodium thiosulfate, Na2S2O3.5H2O, of concentration 0.01 mol / dm3,
(2.5 g / dm3), labelled aqueous sodium thiosulfate

(g) 20 cm3 of 0.2 % starch indicator solution, labelled starch indicator

(h) access to water and distilled water

(i) stop clock or timer

(j) a Bunsen burner and matches

(k) holder for heating the boiling tube

(l) one stirring thermometer, 0–110 °C

Note: Mixing 10 cm3 of solution L with 5 cm3 of aqueous potassium iodide, 3 cm3 of aqueous
sodium thiosulfate and 2 cm3 of starch solution should produce a blue colour within five
minutes.

For Question 2

Each candidate will require

[H] (a) a stoppered test-tube containing about 0.5 g of zinc sulfate crystals, ZnSO4.7H2O, and
0.5 g manganese(IV) oxide, MnO2, intimately mixed and labelled mixture of M and N

(b) one boiling tube and stopper

(c) distilled water

(d) splints

(e) rack of test-tubes

(f) cork or bung to fit test-tubes

(g) filtration apparatus and filter paper

(h) aqueous barium nitrate of suitable concentration to give a positive sulfate test, labelled
barium nitrate solution

[N][H] (i) aqueous silver nitrate of suitable concentration to give a positive halide test, labelled silver
nitrate solution

[C] (j) aqueous nitric acid of concentration 1 mol / dm3, labelled nitric acid

[C] (k) aqueous sodium hydroxide of concentration 1 mol / dm3, labelled sodium hydroxide

(l) aqueous ammonia of concentration 1 mol / dm3, labelled aqueous ammonia

[H] (m) aqueous hydrochloric acid of concentration 2 mol / dm3, labelled hydrochloric acid

(n) 10 volume aqueous hydrogen peroxide – this is equivalent to 0.8 mol / dm3 or a 3 % solution,
labelled hydrogen peroxide

(o) a Bunsen burner, matches and test-tube holder

(p) pH indicator papers and chart

(q) blue litmus papers

(r) teat pipettes

(s) spatula

Labels do not need to include concentrations.

THE SUPERVISOR’S REPORT IS ON PAGES 7 AND 8

This form must be completed and returned in the envelope with the scripts.

REPORT ON PRACTICAL CHEMISTRY

NOVEMBER 2012

1 (a) Supervisor’s Results

It is recommended that the Supervisor should be a chemistry teacher.

(b) The candidate numbers of candidates in each session were:

First session Second session

2 The Supervisor is invited to report details of any difficulties experienced by candidates giving names
and candidate numbers. The report should include reference to:

(a) any general difficulties encountered in making preparations for the examination;

(b) difficulties due to faulty apparatus or materials;

(c) accidents to apparatus or materials.

Other cases of individual hardship, e.g. illness, temporary disability, should be reported direct to
UCLES on the normal Application for Special Consideration form.

NAME OF CENTRE ...............................................................................................................................

CENTRE NUMBER ...................................................

SIGNED .......................................................
Supervisor

DECLARATION (to be signed by the Principal)

The preparation of this practical examination has been carried out so as to maintain fully the security
of the examination.

NAME .....................................................................................................................................................
(in block capitals)

SIGNED .............................................................................................................................. (Principal)

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education
*6376664364*

CHEMISTRY 0620/62
Paper 6 Alternative to Practical October/November 2012
1 hour
Candidates answer on the Question Paper.
No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Answer all questions.

At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question or part
question.
For Examiner’s Use

Total

This document consists of 12 printed pages.

IB12 11_0620_62/2RP
© UCLES 2012 [Turn over
2
For
1 The apparatus below was used to prepare hydrogen and measure the volume of gas Examiner’s
produced. Use

dilute
hydrochloric
acid

metal water

(a) Complete the boxes to identify the pieces of apparatus labelled. [2]

(b) (i) Why would copper metal not be used in this preparation?

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

(ii) Name a suitable metal that could be used in this preparation.

.............................................................................................................................. [2]

[2]

(d) State a test for hydrogen.

test ....................................................................................................................................

result ........................................................................................................................... [2]

[Total: 8]

3
For
2 Hydrogen peroxide breaks down to form oxygen. A student investigated the speed of the Examiner’s
breakdown of aqueous solutions of hydrogen peroxide of different concentrations, using 1 g Use
of powdered manganese(IV) oxide. The temperature was kept constant at 25 °C. She plotted
her results on the grid below.
0.6

0.5

0.4

speed of
reaction 0.3
in cm3 / s

0.2

0.1

0.0
0.0 0.1 0.2 0.3 0.4 0.5
concentration of hydrogen peroxide in mol / dm3

(a) Draw a straight line graph on the grid. [2]

(b) From your graph, work out the speed of the reaction when the concentration of hydrogen
peroxide is 0.5 mol / dm3. Show clearly on the grid how you obtained your answer.

..................................................................................................................................... [2]

(d) (i) What is the function of the manganese(IV) oxide?

.............................................................................................................................. [1]

(ii) Suggest the effect of repeating the investigation using 1 g of lumps of manganese(IV)
oxide. Explain your answer.

effect ..........................................................................................................................

explanation .......................................................................................................... [2]

[Total: 8]

4
For
3 A student prepared zinc nitrate from zinc oxide. Examiner’s
The zinc nitrate was then heated to change it back into zinc oxide. Use
The procedure followed was in three steps.

Step 1 Some zinc oxide was put into a weighed evaporating dish and the mass noted. The
zinc oxide was transferred into a beaker.

Step 2 A dilute acid was slowly added to the beaker until all the zinc oxide had reacted. Zinc
nitrate solution was produced.

Step 3 The solution was evaporated to dryness in the evaporating dish. The resulting solid
was heated in a fume cupboard. After cooling, the dish was weighed. The dish was
then heated again, cooled and reweighed.

The mass of zinc oxide produced was not the same as the amount used at the start.

(a) What could be used to transfer the zinc oxide in Step 1?

..................................................................................................................................... [1]

(b) Name the acid used in Step 2.

..................................................................................................................................... [1]

.............................................................................................................................. [1]

(ii) Why was the dish reweighed in Step 3?

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

.............................................................................................................................. [2]

(d) Suggest two reasons why the amount of zinc oxide produced in Step 3 was not the same
as the mass of zinc oxide used in Step 1.

1 ........................................................................................................................................

2 .................................................................................................................................. [2]

[Total: 7]

5
For
4 A student investigated the reaction of aqueous sodium hydroxide with two different acids, G Examiner’s
and H. Use
Two experiments were carried out.

Experiment 1

Using a measuring cylinder, 20 cm3 of the solution of acid G was poured into a polystyrene
cup. The initial temperature of the solution was measured.

A burette was filled with aqueous sodium hydroxide to the 0.0 cm3 mark.
5.0 cm3 of aqueous sodium hydroxide was added to the solution of G in the cup and the
mixture stirred. The maximum temperature of the solution was measured.

A further 5.0 cm3 of aqueous sodium hydroxide was added to the cup and the mixture stirred.
The maximum temperature of the mixture was measured.

Further 5.0 cm3 portions of aqueous sodium hydroxide were added to the cup, until a total
volume of 40.0 cm3 of sodium hydroxide had been added. After each addition, the mixture
was stirred and the maximum temperatures measured.

6
For
(a) Use the thermometer diagrams in the table to record the temperatures. Examiner’s
Use

maximum temperature
volume of aqueous sodium thermometer
of solution in
hydroxide added / cm3 diagram
polystyrene cup / °C

0.0 25

20
30

5.0 25

20
35

10.0 30

25
40

15.0 35

30
40

20.0 35

30
40

25.0 35

30
40

30.0 35

30
40

35.0 35

30
40

40.0 35

30
[3]

7
For
Experiment 2 Examiner’s
Experiment 1 was repeated using 20 cm3 of the solution of acid H instead of the solution of Use
acid G.

(b) Use the thermometer diagrams in the table to record the temperatures.

maximum temperature
volume of aqueous sodium thermometer
of solution in
hydroxide added / cm3 diagram
polystyrene cup / °C
30

0.0 25

20
30

5.0 25

20
35

10.0 30

25
40

15.0 35

30
40

20.0 35

30
40

25.0 35

30
40

30.0 35

30
40

35.0 35

30
40

40.0 35

30
[3]

8
For
(c) Plot the results for Experiments 1 and 2 on the grid and draw two smooth line graphs. Examiner’s
Clearly label your graphs. Use

35
maximum temperature of solution / °C

20
0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0
volume of aqueous sodium hydroxide added / cm3
[6]

(d) Use your graph to estimate the maximum temperature of the reaction mixture when
8.0 cm3 of aqueous sodium hydroxide was added to 20 cm3 of the solution of acid G.
Show clearly on the graph how you worked out your answer.

..................................................................................................................................... [2]

(e) What type of chemical reaction, other than neutralisation, occurs when acid H reacts with
aqueous sodium hydroxide?

..................................................................................................................................... [1]

9
For
(f) (i) In which experiment was the temperature change greater? Examiner’s
Use
.............................................................................................................................. [1]

(ii) Suggest why the temperature change was greater in this experiment.

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

.............................................................................................................................. [1]

(g) Predict the temperature of the mixture in Experiment 2 after two hours.
Explain your answer.

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

..................................................................................................................................... [2]

[Total: 19]

10
For
5 Two salt solutions, J and K, were analysed. J was aqueous iron(II) sulfate. Examiner’s
The tests on the solutions, and some of the observations, are in the table. Use
Complete the observations in the table.

tests observations

tests on solution J

(a) Appearance of solution J. ................................................................. [1]

(b) To about 1 cm3 of solution J, an equal

volume of aqueous sodium hydroxide was
added. ................................................................. [2]

(c) To about 1 cm3 of solution J, an equal

volume of aqueous ammonia was added. ................................................................. [1]

(d) To about 1 cm3 of solution J, dilute nitric

acid and aqueous silver nitrate were
added. ................................................................. [1]

(e) To about 1 cm3 of solution J, dilute nitric

acid and barium nitrate solution were
added. ................................................................. [2]

tests on solution K

(f) Appearance of solution K. dark pink liquid

(g) To about 1 cm3 of solution K, an equal

volume of aqueous sodium hydroxide was blue precipitate formed
added.

(h) To solution K, aqueous sodium hydroxide

and aluminium powder were added. The
mixture was heated. effervescence, pungent gas evolved

The gas given off was tested. damp red litmus turned blue

11
For
(i) Identify the gas given off in test (h). Examiner’s
Use
..................................................................................................................................... [1]

(j) What conclusions can you draw about solution K?

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

..................................................................................................................................... [2]

[Total: 10]

12
For
6 (a) Ethanoic acid can be prepared by heating ethanol with acidified potassium Examiner’s
manganate(VII). Use
Give a test to distinguish between ethanoic acid and ethanol.

test ....................................................................................................................................

result ........................................................................................................................... [2]

(b) Coal is a fossil fuel. When heated strongly, sulfur dioxide gas is one of the products
formed.
Sulfur dioxide changes the colour of acidified potassium manganate(VII) from purple to
colourless.
Plan an investigation to show which of the two different types of coal produces the most
sulfur dioxide when heated. You are provided with one lump of each type of coal.

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

..................................................................................................................................... [6]

[Total: 8]

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

MARK SCHEME for the May/June 2012 question paper

for the guidance of teachers

0620 CHEMISTRY
0620/12 Paper 1 (Multiple Choice), maximum raw mark 40

Mark schemes must be read in conjunction with the question papers and the report on the
examination.

• Cambridge will not enter into discussions or correspondence in connection with these mark schemes.

Cambridge is publishing the mark schemes for the May/June 2012 question papers for most IGCSE,
GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level
syllabuses.
Page 2 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 12

Question Question
Key Key
Number Number
1 C 21 A
2 D 22 C
3 D 23 B
4 B 24 A
5 C 25 C

6 C 26 A
7 B 27 B
8 B 28 D
9 B 29 A
10 D 30 A

11 D 31 C
12 A 32 D
13 C 33 A
14 C 34 A
15 D 35 C

16 C 36 A
17 C 37 C
18 B 38 B
19 C 39 D
20 B 40 D

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

MARK SCHEME for the May/June 2012 question paper

for the guidance of teachers

0620 CHEMISTRY
0620/22 Paper 2 (Core Theory), maximum raw mark 80

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of
the examination. It shows the basis on which Examiners were instructed to award marks. It does not
indicate the details of the discussions that took place at an Examiners’ meeting before marking began,
which would have considered the acceptability of alternative answers.

Mark schemes must be read in conjunction with the question papers and the report on the
examination.

• Cambridge will not enter into discussions or correspondence in connection with these mark schemes.

1 (a) carbon dioxide → turns limewater milky; [1]

chlorine → bleaches damp litmus paper; [1]
oxygen → relights a glowing splint; [1]
hydrogen → pops with a lighted splint; [1]

(b) (i) manganese(IV) oxide + hydrochloric acid → manganese chloride + chlorine + water [3]
note: –1 mark per error
allow: manganese oxide (on left)
ignore: incorrect oxidation numbers of manganese chloride

(ii) C [1]

(c) (i) O2 (on left); [1]

correct balance dependent on O2 or 2O on left i.e. 2 (on right); [1]

(ii) hydrogen: for fuel / as a reducing agent / any other specific use
e.g. manufacture of margarine, making ammonia [1]
water: any suitable use e.g. coolant / washing / cooking / drinking etc. [1]

[Total: 12]

2 (a) sodium hydroxide solution; [1]

(b) any pH above 7; [1]

(c) any two of: [2]

place indicator into solution;
universal indicator paper or solution / pH meter;
compare colour with pH colour chart / take reading on pH meter;

(d) (i) plants might die / to allow good crop growth / good growth of grass etc. [1]

(ii) any two of: [2]

calcium carbonate is a base;
reacts (with acids);
neutralises (the acid);
[Total: 7]

3 (a) (i) chlorine: (light) green; [1]

not: yellow
bromine: brown / red / red-brown; [1]

(ii) chlorine: the boiling point is below / less than / lower than room temperature; [1]
bromine: the melting point is below / less than / lower than room temperature and the
boiling point is above / higher than room temperature: [1]

(iii) any value between +190 °C to 450 °C [1]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 22

(b) (i) I2 (on the right) [1]

correct balance i.e. 2 on left (if I2 or 2I on right) [1]

(ii) potassium chloride; iodine; [2]

(iii) 3 [1]

(c) nitric; silver; yellow; precipitate; [4]

[Total: 14]

4 (a) (i) B; [1]

(ii) C; [1]

(iii) D; [1]

(b) lightning activity / car engines / high temperature furnaces; [1]

(d) 46; [1]

(e) (i) CO / carbon monoxide; [1]

gains oxygen; [1]
allow: oxidation number of carbon increases / loss of electrons

(ii) substance which speeds up a reaction / increases reaction rate; [1]

(iii) amount of oxygen reduced; [1]

so incomplete combustion occurs / the carbon is not fully oxidised; [1]

(iv) CO is poisonous / toxic; [1]

allow: higher level answers e.g. combining with haemoglobin / haem

[Total: 12]

5 (a) any three of:

hard / high density / high melting (or boiling) points;
allow: forms coloured compounds / general metallic properties [3]

(b) (i) iron + sulfuric acid → iron sulfate + hydrogen [2]

note: –1 per error

Page 4 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 22

(ii) suitable apparatus for measuring gas volume e.g. syringe / upturned measuring cylinder;
[1]
closed system; [1]
measure volume of gas; [1]
at given time intervals; [1]
ALLOW: (for max 3 marks) unstoppered flask on top of balance (1)
measure decrease in mass of flask (1)
at given time intervals (1)

(c) (i) exothermic; [1]

(ii) two (or more) different atoms / elements bonded / joined together; [1]
note: both atoms / elements and bonded / joined needed

(iii) FeS; [1]

[Total: 12]

6 (a) X drawn in bottom compartment or in tube leading from arrow showing petroleum in; [1]

(b) naphtha [1]

(c) kerosene: jet fuel / fuel for heating / cooking fuel / kerosene lamps; [1]
diesel: fuel for lorries / cars / tractors; [1]

(d) mixture; heated; lower; condenses; boiling; [5]

(e) (i) B and D; [1]

(ii) B and D [2]

[Total: 12]

7 (a) any 4 of:

in solid salt the particles can’t move / fixed;
salt dissolves / dissolving;
(because) forces between particles / ions (in solid) are overcome;
diffusion;
salt particles in solution move;
randomly;
water particles moving;
water and salt particles (constantly) colliding;
salt particles spread themselves out or mix with water; [4]

(b) (i) a sodium atom loses its outermost electron and a chlorine atom gains an electron / 2nd
box down ticked; [1]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 22

(ii) in solid sodium chloride, the ions can’t move / fixed; [1]
in molten sodium chloride the ions can move / free; [1]

(iii) positive electrode: chlorine; [1]

negative electrode: hydrogen; [1]

(iv) cathode; [1]

(v) conducts electricity; [1]

allow: non-reactive / inert;

[Total: 11]

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

MARK SCHEME for the May/June 2012 question paper

for the guidance of teachers

0620 CHEMISTRY
0620/32 Paper 3 (Extended Theory), maximum raw mark 80

Mark schemes must be read in conjunction with the question papers and the report on the
examination.

• Cambridge will not enter into discussions or correspondence in connection with these mark schemes.

1 (a) neon has full outer shell / energy level / valency shell / octet / 8 (electrons) in outer shell /
neon does not need to lose or gain electrons; [1]
fluorine atoms have 7 electrons / needs 1 to fill / has incomplete shell / forms bonds with
other fluorine atoms / fluorine (atoms) form covalent bonds / shares electrons; [1]

(b) atomic number / proton number / number of protons (in one atom); [1]

(c) weak intermolecular (or between molecules) forces / Van der Waals forces between
molecules / low amount of energy required to break bonds between molecules; [1]
strong bonds don’t break / covalent bonds don’t break / (unnamed) bonds within molecules /
between atoms don’t break; [1]

(d) 1 non-bonding pair on each nitrogen atom; [1]

6 electrons between nitrogen atoms; [1]

2 (a) weak forces between layers or between (hexagonal) rings / weak bonds between layers or
between (hexagonal) rings / Van der Waals forces between layers or between (hexagonal)
rings; [1]
(layers/rings) slip/slide (over each other) / move over each other [1]

(b) strong bonds (between atoms) / covalent bonds (between atoms); [1]
all bonds are covalent/strong / each atom covalently bonded / carbon (atoms) is bonded to
four others / bonds are directional / (atoms are arranged) tetrahedrally; [1]
accept: carbon has four bonds

(c) graphite has delocalised / mobile / free electrons; [1]

diamond (outer shell) electrons used / fixed / localised in bonding / no delocalised electrons /
no mobile electrons / no free electrons; [1]

3 (a) flexible / easily form different shapes / easily moulded / bends (without cracking); [1]
non-biodegradable / unreactive / don’t corrode / prevent corrosion / prevent oxidation (of the
conducting metal) / water resistant / waterproof; [1]

(b) improve appearance / decorative / makes appearance shiny; [1]

prevent corrosion / rusting / protect steel / chromium will not corrode / chromium is not
oxidised / chromium protected by an oxide layer; [1]

(c) low density / light / protected by oxide layer / no need to paint / resists corrosion / (high)
strength / strong;; any two [2]
note: high strength to weight ratio = 2

(d) high mpt / withstands high temperature / good conductor (of heat) / heats up quickly /
malleable / ductile / resists corrosion / good appearance / unreactive (or example of lack of
reactivity e.g. does not react with food or water or acid or air);; any two [1]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 32

(e) (lattice) positive ions / cations / metal ions and sea of electrons / delocalised or free or mobile
or moving electrons; [1]
attraction between positive ions and electrons; [1]

4 (a) (i) oxygen; [1]

carbon dioxide / fluorine / carbon monoxide; [1]

(ii) decrease mpt (of alumina/Al2O3) / lower (operating) temperature (from 1900/2100 (°C) to
800/1000 (°C) / reduce energy (accept heat or electrical) requirement; [1]
improve conductivity / dissolves the Al2O3 / acts as solvent; (allow: makes aluminium
oxide conduct / to conduct electricity / making ions free to move) [1]

(iii) Al2O3 (accept alumina) reacts / dissolves / forms a salt and water / is neutralised; [1]
(Fe2O3 removed by) filtration / centrifugation / decantation; [1]

(b) (i) electrolysis / electrolyte / electrodes / anode / cathode / electricity / cell; [1]
chlorine formed at anode (positive electrode); (note: can be awarded from a correct or
incorrect equation with Cl2 as the only substance on the right as long as anode is
mentioned.) [1]
hydrogen formed at cathode (negative electrode); (note: can be awarded from a correct
or incorrect equation with H2 as the only substance on the right as long as cathode is
mentioned.) [1]
one correct half equation either 2Cl – → Cl2 + 2e or 2H+ + 2e → H2 [1]
solution remaining contains Na+ and OH– / sodium and hydroxide ions / NaOH / sodium
hydroxide left behind/remains in solution; [1]

note: if a mercury cathode is specified

electrolysis / electrolyte / electrodes / anode / cathode / electricity / cell; [1]
chlorine formed at anode (positive electrode); (note: can be awarded from a correct or
incorrect equation with Cl2 as the only substance on the right as long as anode is
mentioned.) [1]
sodium formed at cathode; (note: can be awarded from a correct or incorrect equation
with Na as the only substance on the right as long as cathode is mentioned.) [1]
one correct half equation at anode i.e. 2Cl – → Cl2 + 2e or at cathode Na+ + e → Na
(accept: equivalent with NaHg amalgam) [1]
NaOH/sodium hydroxide is formed by sodium/sodium mercury amalgam reacting with or
when added to water; [1]
note: award the fourth and fifth mark if correct equation given for reaction between
sodium or sodium mercury amalgam reacting with water i.e.
2Na(Hg) + 2H2O → 2NaOH + H2 + (2Hg)

(ii) H2 / H / hydrogen and making ammonia / making margarine / hardening fats / fuel /
energy source / cryogenics / welding; [1]
Cl2 / Cl / chlorine and (making) bleach / water treatment / kill bacteria (in water) / water
purification / swimming pools / making solvents / making PVC / making weed killer /
making disinfectants / making hydrochloric acid / HCl / making herbicides / pesticides /
insecticides; [1]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 32

5 (a) (i) correct -O- linkage; [1]

correct unit and continuation -O-- (minimum); [1]

(ii) any name or correct formula of a (strong) acid / H+; [1]

(iii) contain carbon hydrogen and oxygen /C, H and O; [1]

(b) (i) glucose → ethanol + carbon dioxide [1]

(ii) yeast is catalyst / provides enzymes / speeds up reaction / too slow without yeast; [1]
yeast cells grow / multiply / reproduce / undergo budding / breed; [1]

(iii) heat or high temperature would kill yeast (cells) / heat or high temperature denatures
enzymes; [1]
not: enzyme killed / denatures yeast
reduces rate of reaction / slows reaction / (yeast or enzyme) no longer catalyses / no
catalyst / stops reaction / no more product; [1]

(c) (i) would produce carbon dioxide or carboxylic or organic acids (if oxygen is present) / to
prevent aerobic respiration / so products are not oxidised / anaerobic bacteria can’t live
with oxygen; [1]

(ii) fossil fuels have a reduced need / conserved / no need to import / will last longer /
cracking hydrocarbons to make methane no longer required;
(methane) is renewable / carbon neutral;
reduce pollution of water or sea / prevents visual pollution / prevents need for waste
disposal or accumulation (accept: any methods of waste disposal) / so that waste is
recycled; any two [2]

6 (a) (i) A C D B [1]

(ii) speed (or rate) increases as concentration increases / time decreases as concentration
increases; [1]
rate or speed or time depends on (concentration) of H+ or hydrogen ions; [1]
B is slow because propanoic acid is weak or doesn’t dissociate or weakly ionises;
or
B is slow because HCl and H2SO4 are stronger or ionise or dissociate more than
propanoic; [1]
D slower than C because C is more concentrated than D / ORA; [1]
A is fast because H+ concentration high (note: this would also score second mark if not
already awarded) / H2SO4 is diprotic or dibasic or 2H+; [1]
time is inversely proportional to rate / owtte / ORA; [1]
max [5]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 32

(b) change 1:
increase temperature / heat (the mixture); [1]
particles/molecules/ions have more energy or move faster; [1]
more (successful) collisions / more particles with Ea; [1]
change 2:
increase surface area / decrease particle size / use powdered (magnesium) / use smaller
pieces / crush the magnesium; [1]
more collisions / more particles exposed to reaction; [1]
or
catalyst; [1]
more (successful) collisions; [1]
lowers Ea; [1]
max [5]

7 (a) (i) CH2/H2C [1]

(ii) same ratio of C:H (atoms) / all cancel to CH2 / because general formula is CnH2n / same
ratio of atoms or elements (in the compound) / C:H ratio is 1:2; [1]

(b) (i) propanoic / propionic (acid); [1]

ethanoic / acetic (acid); [1]

(ii) formula of ethene / but-2-ene / any symmetrical alkene; [1]

(c) (i) CH3CH(Br)CH2Br [1]

(ii) CH3CH(OH)CH3 / CH3CH2CH2OH / C3H7OH [1]

(d)

correct unit; [1]

accept: more than one repeat unit
continuation bonds at both ends; [1]

(e) if C5H10 is given award 3 marks;;; [3]

if C10H20 is given award 2 marks;;
if 1:7.5:5 / 2:15:10 is given award 2 marks;;
in all other cases a mark can be awarded for moles of O2 (= 2.4/32 =) 0.075 AND moles
of CO2 (= 2.2/44 =) 0.05;

2C5H10 + 15O2 → 10CO2 + 10H2O [1]

accept: multiples including fractions
allow: ecf for correct equation from any incorrect alkene

Page 6 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 32

8 (a) proton donor; [1]

(b) equal concentrations of both (solutions); [1]

add Universal indicator / determine pH / pH paper; [1]
ethylamine has lower pH / ORA; [1]
or
equal concentration of both (solutions); [1]
measure conductivity of aqueous ethylamine and sodium hydroxide; [1]
ethylamine will have lower conductivity / sodium hydroxide will have higher conductivity; [1]

(c) add strong(er) base / NaOH / KOH; [1]

warm / heat; [1]

(d) (ethylamine forms) hydroxide ions / OH– (in water); [1]

hydroxide ions / OH– reacts with iron(III) ions / Fe3+;
or
iron(III) hydroxide / Fe(OH)3 (forms as a brown precipitate); [1]
note: balanced or unbalanced ionic equation i.e. Fe3+ + (3)OH– → Fe(OH)3 scores both
marks

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

MARK SCHEME for the May/June 2012 question paper

for the guidance of teachers

0620 CHEMISTRY
0620/52 Paper 5 (Practical), maximum raw mark 40

Mark schemes must be read in conjunction with the question papers and the report on the
examination.

• Cambridge will not enter into discussions or correspondence in connection with these mark schemes.

1 (a) experiment 1 all boxes completed (1)

results show a regular pattern (1) [2]

(b) experiment 2 all boxes completed (1)

results show a regular pattern (1) [2]

(c) all points correctly plotted (+/– ½ small square) (2), –1 for any incorrect
Should have a y axis:
linear scale and points extend over at least 4 big squares (8 cm) (1)
two × smooth lines (curved or straight) (2)
both lines labelled (1) [6]

(d) (i) value from graph (+/– ½ small square) (1) shown clearly (1) [2]

(ii) value from graph (+/– ½ small square) (1) shown clearly (1) [2]

(e) endothermic (1) [1]

(f) lower temperature (changes) (1)

greater volume/more water (1) [2]

(g) room temperature or initial temperature from table (1)

reaction finished/all dissolved/warms up (1) [2]

(h) more readings/points (1)

better graph/more reliable/more accurate/owtte (1) [2]

[Total: 21]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 52

2 (a) green (1) reject: any other colours, ignore: dark/light [1]

(b) (turns) black (1) condensation/drops at top of tube/steam/water (1)

limewater (1) milky/cloudy/white ppt (1) max 3 [3]

(c) (i) fizz/bubbles etc. (1)

blue solution/liquid (1) [2]

(ii) blue (1) ignore: qualifiers such as dark/light precipitate (1) [2]
blue precipitate (1) (ignore qualifiers such as dark/light)

(iii) dark/royal/deep blue (1) must be some indication it is darker than the ppt
solution/soluble/dissolves (1) [3]

(d) appearance: colourless (1)

smell: vinegar/pungent/sharp/sour/strong (1) [2]

(e) pH2–6 (1) [1]

(f) green or blue-green solution/liquid (1)

fizz/bubbles (1) [2]

(g) copper (1) carbonate (1) [2]

(h) acid/organic/ethanoic/acetic/vinegar [1]

[Total: 19]

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

MARK SCHEME for the May/June 2012 question paper

for the guidance of teachers

0620 CHEMISTRY
0620/62 Paper 6 (Alternative to Practical), maximum raw mark 60

Mark schemes must be read in conjunction with the question papers and the report on the
examination.

• Cambridge will not enter into discussions or correspondence in connection with these mark schemes.

1 (a) beaker (1) [1]

(b) any through tube with (only) two open ends (1)
outer tube with ‘water’ labelled and a way in and out (1) [2]

(c) turns red/pink (1)

reversible/rehydration/owtte/CoCl2 going pink is the test for water (1) [2]

(d) water condensed at top of tube (1)

runs back onto hot tube/water onto CoCl2 generates heat/owtte (1) not: suck back [2]

[Total: 7]

2 (a) smooth curve starting at origin and missing anomalous point (1) [1]

(b) point at 1.5 min/4th point/0.32 g (1) ignore: 3rd point [1]

(c) reaction finished/no more gas (1)

magnesium carbonate used up (1) [2]

(d) rising part of sketch curve below the original/less steep (1)
to half final level/0.25 g (1) [2]

[Total: 6]

3 (a) bulb/lamp lights/water level falls/green-yellow gas (1) [1]

(b) arrows labelling electrodes as anode/cathode or + – or the electrodes or Pt (1)

allow: labels either way round not: the wires labelled [1]

(c) (i) hydrogen (1) [1]

(ii) lighted splint (1) if Cl2 in (c)(i) allow ecf for damp litmus/indicator paper
no ecf for anything other than Cl2

pops (1) if Cl2 in (c)(i) allow ecf for bleached/white/decolourised [2]

note: These are conditional marks so the result is conditional on the test, i.e. glowing
splint pops = 0/2

(d) chlorine (1) soluble/dissolves/reacts (1) [2]

[Total: 7]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 62

4 (a) fizzing/bubbles stopped/no more gas produced (1) [1]

(b) (i) W little/no effect/slight increase (1)

X no effect/(slight) decrease (1)
Y speeds up reaction (1) [3]
note: The question is about rate, if candidates quote three different time differences,
penalise first then allow the ‘correct’ answers (–11 s, +2 s, –199 s).
It must be clear that the increase in rate is less for W than Y for these 2 marks.

(ii) Y (1) [1]

[Total: 7]

5 (a) temperature boxes correctly completed (2) 21, 25, 26, 27, 27, 26, 25 [2]

(b) temperature boxes completed correctly (2) 20, 19, 18, 17, 17, 18, 19 [2]

(c) all points correctly plotted (3), –1 for any incorrect

smooth line graphs (2)
labels (1) [6]

(d) (i) value from graph (1) allow: ±1/2 small square shown clearly (1) [2]

(ii) value from graph (1) allow: ±1/2 small square shown clearly (1) [2]

(e) endothermic (1) ignore: temperature decreases [1]

(f) lower temperature (change)/halved (1) ignore: reference to rate/time [1]

(g) room temperature/initial temperature from table/20°C/21°C (1) ignore: 25°C

reaction finished/owtte (1) [2]

(h) more readings/more points (1)

more reliable/more accurate (1) ignore: precise
can spot anomalous points or errors (1)
smoother graph/owtte (1) any [2]

[Total: 20]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper
IGCSE – May/June 2012 0620 62

6 (d) appearance colourless (1) ignore: clear

smell vinegar/pungent/sour/sharp (1) ignore: sweet/strong [2]

(e) pH 2–6 (1) [1]

(f) carbon dioxide (1) [1]

(g) copper/Cu2+ (1) carbonate/CO32– (1) [2]

[Total: 6]

7 (a) use Universal/pH indicator/pH meter (1) ignore: litmus/indicator [1]

(b) note: This can be marked via three routes.

If they use a full bottle:

use full bottle (1)
(air-tight) connections (1)
syringe/inverted measuring cylinder/graduated tube to collect gas (1)
heat/shake (1)
until no more gas given off (1)
measure volume of gas (1)
any 6

If they use a sample:

use measured volume (1)
(air-tight) connections (1)
syringe/inverted measuring cylinder/graduated tube to collect gas (1)
heat/shake (1)
until no more gas given off (1)
measure volume of gas (1)
multiply to get full bottle value (1)
max 6

If they do it by loss in mass:

weigh the bottle/sample (1)
heat/shake (1)
until no more gas given off (1)
reweigh bottle (1)
use density to calculate volume (1)
max 5 [6]

[Total: 7]

CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

MARK SCHEME for the October/November 2012 series

0620 CHEMISTRY
0620/12 Paper 12 (Multiple Choice), maximum raw mark 40

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers.

Cambridge will not enter into discussions about these mark schemes.

Cambridge is publishing the mark schemes for the October/November 2012 series for most IGCSE, GCE Advanced
Level and Advanced Subsidiary Level components and some Ordinary Level components.
Page 2 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 12

Question Question
Key Key
Number Number

1 C 21 B
2 C 22 C
3 B 23 B
4 A 24 D
5 B 25 C

6 A 26 A
7 B 27 A
8 D 28 A
9 D 29 A
10 A 30 D

11 D 31 D
12 A 32 C
13 D 33 B
14 B 34 D
15 C 35 A

16 C 36 C
17 D 37 C
18 B 38 C
19 D 39 A
20 C 40 A

CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

MARK SCHEME for the October/November 2012 series

0620 CHEMISTRY
0620/22 Paper 2 (Core Theory), maximum raw mark 80

Mark schemes should be read in conjunction with the question paper and the Principal Examiner
Report for Teachers.

Cambridge will not enter into discussions about these mark schemes.

Cambridge is publishing the mark schemes for the October/November 2012 series for most IGCSE,
GCE Advanced Level and Advanced Subsidiary Level components and some Ordinary Level
components.
Page 2 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 22

1 (a) (i) D / phosphorus / P; [1]

(ii) E / helium / He; [1]

(iii) C / chlorine / Cl2 / Cl; [1]

(iv) A / copper / Cu; [1]

(v) A / copper / Cu; [1]

(b) C; D; [2]

(c) giant; covalent; [2]

(d) substance containing only 1 type of atom / substance which cannot be broken down into a
simpler one; [1]
allow: substance which can’t be separated by chemical means
ignore: substance with one atom / substance with similar types of atom

[Total: 10]

2 (a) (damp) red litmus (paper); [1]

turns blue; [1]
note: second mark dependent on correct reagent
allow: universal indicator (1 mark); turns blue / purple (1 mark)
allow: 1 mark for litmus paper turns blue / pH paper turns blue
allow: white fumes (1 mark); with hydrochloric acid vapour (1 mark)
ignore: other chemicals added as long as it is clear that ammonia is the gas being tested

(b) pH 9; [1]

(c) (i) NH4Cl on right; [1]

(ii) structure completely correct;; [2]

allow: 1 mark for 1 pair of electrons bonded between H and Cl
ignore: inner shell electrons

Page 3 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 22

(d) (i) any 4 of: [4]

use of burette
add indicator to flask
add acid to alkali (or vice versa)
until indicator changes colour
record volume (of acid or alkali added) ignore: amount of acid or alkali added
repeat without indicator
using same volume of acid and ammonia as in previous experiment

(ii) heat to crystallisation (point) / evaporate some of the water / leave to crystallise [1]
allow: heat then cool
ignore: heat (unqualified) / heat to dryness / heat to get rid of all the water

[Total: 11]

3 (a) (i) get darker / deeper colour; [1]

(ii) gas; [1]

allow: answer written in table

(iii) any value between –180 to –20 °C (actual = –101 °C); [1]
allow: answer written in table

(b) (i) chlorine → bromine → iodine → astatine;; [2]

allow: 1 mark if one pair incorrect way round / order completely reversed

(ii) no and chlorine is more reactive (than bromine) / bromine is less reactive; [1]
ignore: chlorine is very reactive / bromine is not very reactive
ignore: chloride is more reactive

(c) H2O (on right); [1]

2 on left (this is dependent on H2O being the product); [1]

(d) (i) to kill bacteria / to kill microbes / to disinfect it [1]

allow: to kill germs / to get rid of bacteria
ignore: to clean water

(ii) any two of: [2]

minerals or (dead) remains insoluble in water
these particles are large / water particles (molecules) are very small
(larger particles) get stuck (between the sand particles) / (larger particles) remain in the
sand / trapped by sand
water (molecules) drain through / water comes out the bottom
ignore: water is filtered

[Total: 11]

Page 4 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 22

4 (a) groups of hydrocarbons / molecules; [1]

with similar (range of) boiling points / sizes / masses; [1]
allow: 1 mark for idea of separating molecules for particular fuels
ignore: petroleum broken down / smaller molecules formed / mixture of fuels

(b) (i) gasoline; diesel; [2]

(ii) refinery gas: heating / cooking; [1]

allow: fuel
bitumen: roads / roofing; [1]

(c) high temperature; [1]

allow: heat / stated temperature of 200 °C or more
catalyst; [1]
ignore: name of catalyst
ignore: pressure

(d) (i) substance containing hydrogen and carbon only; [1]

(ii) C4H8 / 2C2H4; [1]

(e) (i) H H [1]

│ │
C=C
│ │
H H

(ii) monomers; addition; polymers; [3]

[Total: 14]

Page 5 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 22

5 (a) any two of; [2]

Al has low density / iron has high density
allow: lightweight or light for density)
Al does not form coloured compounds / iron formed coloured compounds
Al has only one oxidation state / iron has several oxidation states
Al does not act as a catalyst / iron can act as a catalyst
Al is softer / iron is harder (comparative needed)
Al has lower density / iron has higher density (comparative needed)
Al is a better conductor / iron is not as good a conductor (comparative needed)
Al is weaker / iron is stronger (comparative needed)
ignore: melting and boiling points

(b) any suitable use e.g. aircraft or car (bodies) / food containers / pots and pans / electrical
wiring / drinks cans; [1]

(c) precipitate formed; [1]

which is white in colour; [1]
dissolves (in excess sodium hydroxide); [1]
allow: precipitate disappears

[Total: 6]

6 (a) (i) limestone / chalk; [1]

(ii) the other product is a gas / carbon dioxide escapes; [1]

allow: carbon dioxide is a gas / waste gases are gone / CO2 formed
allow: reaction goes completely to the right

(b) (i) C + O2 → CO2;; [2]

allow: 1 mark for O2 as reactant / C + 2O → CO2

(ii) limited; air; monoxide; poisonous; [4]

allow: oxygen in place of air
note: if dioxide put in third position allow 1 mark for harmless in 4th position

(c) calcium chloride; [1]

water; [1]

(d) (i) idea of measure the (decrease in) mass / weight; [1]
idea of measuring time (intervals); [1]

(ii) increases / faster; [1]

decreases / slower; [1]
increases / faster; [1]
note: the answers above must be comparative
allow: 1 mark for fast; slow; fast
ignore: reference to time taken

[Total: 15]

Page 6 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 22

7 (a) (i) any 4 of: [4]

(at 20 °C / at the start) particles are close together / touching / arranged regularly
(at 20 °C / at the start) particles are vibrating / not moving
as temperature rises / then particles vibrate more / gain energy
at 114 °C / then particles begin to move
forces between particles weaken / molecules start to break away (from each other)
at 114 °C / then particles become more randomly arranged / slide over each other
when liquid / above 114 °C / then particles slide over each other/ move
when liquid / above 114 °C then particles are randomly arranged
ignore: particles further apart / particles (move) faster

(ii) 254; [1]

(b) (i) ionic; [1]

(ii) KI; [1]

(c) (1 each) [4]

insoluble / does not dissolve; doesn’t conduct;
soluble / dissolves; doesn’t conduct;
ignore: low / high / not very well

(d) + electrode: iodine / I2 / I; [1]

– electrode: potassium / K; [1]
allow: 1 mark if correct electrode products reversed
ignore: iodide

[Total: 13]

CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

MARK SCHEME for the October/November 2012 series

0620 CHEMISTRY
0620/32 Paper 3 (Extended Theory), maximum raw mark 50

Mark schemes should be read in conjunction with the question paper and the Principal Examiner
Report for Teachers.

Cambridge will not enter into discussions about these mark schemes.

Cambridge is publishing the mark schemes for the October/November 2012 series for most IGCSE,
GCE Advanced Level and Advanced Subsidiary Level components and some Ordinary Level
components.
Page 2 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 32

1 (a) (i) Sb;

(ii) Xe / B;

(iii) Sr / Te / A / D;

(iv) Sn and I / E and F;

(v) Sr / A; [5]

(b) any two from:

physical
niobium is
harder; stronger; higher mp/bp; higher density [2]
note: there has to be a comparison

any two from:

chemical
niobium is less reactive; forms coloured compounds; forms complex ions; its
compounds have catalytic properties; has more than one oxidation state; has more
than one valency electron; [2]
note: the response has to refer to or compare properties of both elements

[Total: 9]

2 (a) liquid; [1]

(b) (l) and (s); [1]

reversible sign; [1]
accept: X in equation
ignore: any compounds just look for state symbols
must be the same compound on both sides of equation

(c) boiling / condensation; [1]

accept: evaporation or vaporisation

(d) (in region BC) solid melts / liquid boils (in region DE); [1]
at one / fixed / sharp / single / specific temperature; [1]

[Total: 6]

3 (a) (i) correct structure of an isomer e.g. 2-chloropropane; [1]

(ii) chlorine; [1]

light / heat / lead tetraethyl; [1]

Page 3 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 32

(iii) could produce 2-chloropropane; [1]

could produce HCl; [1]
or
could produce dichloropropanes = [2]

(b) (i) add silver nitrate / lead nitrate; [1]

yellow precipitate; [1]
note: do not insist on presence of dilute nitric acid

(ii) propanol / propan-1-ol; [1]

(c) (i) for A;

reaction slower;
decreased collision rate;
less bromobutane present / concentration of bromobutane less / less reacting
particles; [2]
any two
accept: reverse arguments for B

(ii) halogens Cl > Br > I reactivity / reactivity decreases down group; [1]
organic halides I > Br > Cl / reactivity increases down group; [1]
opposite without explanation = [1]

(iii) any three from:

less energy;
particles move slower;
less collisions / fewer particles have energy to react / fewer successful collisions;
slower rate; [3]

[Total: 15]

4 (a) C + O2 → CO2 [1]

(b) (i) CO2 already formed (from C burning or from CaCO3); [1]
then carbon reacts with carbon dioxide; [1]
or
C + CO2 → 2CO = [2] If equation not balanced = [1]

(ii) Fe2O3 + 3CO → 2Fe + 3CO2 [2]

not balanced = [1]
not: reduction by carbon

(c) to remove / neutralise silica / silicon dioxide / silicon(IV) oxide / sand; [1]
reacts with limestone to form slag / calcium silicate; [1]
CaCO3 + SiO2 → CaSiO3 + CO2 [1]
or CaO + SiO2 →CaSiO3
or CaCO3 → CaO + CO2

Page 4 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 32

(d) (i) galvanising / galvanisation / sacrificial protection; [1]

(ii) sacrificial protection / zinc is sacrificed;

zinc corrodes rather than iron;
zinc is oxidised in preference to iron;
zinc reacts with oxygen and / water in preference to iron;
zinc more reactive / electropositive than iron;
zinc loses electrons more readily than iron;
electrons move on to iron
any three [3]

[Total: 12]

5 (a) any two from:

bleaching (wood pulp / silk / straw);
manufacture of sulfuric acid / SO3 / in Contact process;
fumigating / sterilising; refrigerant; making dyes; making wine; insecticide;
fungicide; [2]

(b) burn / heat / react sulfur; [1]

in air / oxygen; [1]
or
burn / heat / roast zinc sulfide or lead sulfide;
in air / oxygen;

(c) from purple / pink; not: red [1]

to colourless; not clear [1]

(d) number of moles of Na2SO3 = 3.15/126 = 0.025 [1]

number of moles of SO2 formed = 0.025 [1]
volume of SO2 = 0.025 x 24 = 0.6 dm3/litres or 600 cm3 [1]
allow: ecf
for 1.6 g of SO2 [1] only
If used 22.4 max [2]
note: need correct units for last mark

[Total: 9]

Page 5 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 32

6 (a) (i) correct arrow from negative terminal of battery or from anode; [1]

(ii) from battery / power supply / cell; [1]

from negative electrode of battery to external circuit; [1]
or from anode;
from iodide ion losing electron or oxidation of anion;

(iii) ions cannot move in solid / ions can move in liquid; [1]

(b) copper; [1]

(changes to) sulfuric acid; [1]

hydrogen; [1]
(changes to) potassium hydroxide; [1]

(c) (i) 2H+ + 2e H2 [2]

not balanced = [1]

(ii) 4OH- O2 + 2H2O + 4e [1]

(iii) water used up; [1]

(d) it is a cell; [1]

hydrogen reacts with oxygen; [1]
this reaction produces energy / is exothermic / produces flow of electrons /
changes chemical energy to electrical energy; [1]

[Total: 15]

7 (a) (i) CnH2n+1OH [1]

(ii) 116-17 = 99, 2n+1 = 99, n = 7

for any evidence of working out [1]
C7H15OH [1]

(iii) 4bps around C; [1]

1 bp on each hydrogen; [1]
2bps and 2nbps on oxygen; [1]

(b) (i) increases yield / moves equilibrium to RHS / favours forward reaction; [1]
high pressure favours side with smaller number of (gas) molecules; [1]

(ii) any two from:

higher temperature / catalyst causes faster reaction;
comment about compromise conditions to give best rate and yield;
at 250oC (lower temp) higher yield / forward reaction favoured;
at 350oC (higher temp) lower yield / back reaction favoured; [3]

Page 6 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 32

(c) (i) methanoic acid; [1]

correct SF showing all bonds; [1]
accept: -OH

(ii) methyl methanoate; [1]

[Total: 14]

CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

MARK SCHEME for the October/November 2012 series

0620 CHEMISTRY
0620/52 Paper 5 (Practical), maximum raw mark 40

Mark schemes should be read in conjunction with the question paper and the Principal Examiner
Report for Teachers.

Cambridge will not enter into discussions about these mark schemes.

Cambridge is publishing the mark schemes for the October/November 2012 series for most IGCSE,
GCE Advanced Level and Advanced Subsidiary Level components and some Ordinary Level
components.
Page 2 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 52

1 (e) Table of results for Experiments

all initial temperature boxes completed correctly as instructed (1)

all final temperature boxes completed correctly not more than 20 °C below original (1)

all average temperatures completed correctly (1)

times completed in seconds (1) ignore: dps

descending in order (comparable to supervisor) (1) [5]

(f) points plotted correctly (4)

smooth line graph (1) [5]

(g) average temperature 72 °C (1)

value from graph (1)

extrapolation shown on grid (1) [3]

(h) as an indicator/check presence of iodine owtte (1) [1]

(i) (i) experiment 5/when temperature is 70 (1) [1]

(ii) highest temperature (1)

particles have more energy/more collisions (1) [2]

(j) time longer/more/increase (1)

speed slower/decrease (1) [2]

(k) more accurate (1) [1]

2 (a) pH 5–7 (1) ignore colours [1]

(b) (i) white (1) precipitate (1) dissolves owtte (1) [3]

(ii) white (1) precipitate (1) dissolves owttte (1) [3]

(c) no reaction/no change/no precipitate/no observation (1) [1]

(d) white (1) precipitate (1) [2]

2
Page 3 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 52

(e) litmus turns red (1) then bleached/white (1) [2]

(f) bubbles/fizz etc. (1)

glowing splint (1) glows brighter/relights (1) [3]

(g) zinc (1) sulfate (1) [2]

(h) oxygen (1) [1]

(i) transition metal present (1) catalyst (1)

manganese/copper (1) oxide (1) max 2 [2]

[Total: 40]

3
CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education

MARK SCHEME for the October/November 2012 series

0620 CHEMISTRY
0620/62 Paper 6 (Alternative to practical), maximum raw mark 60

Mark schemes should be read in conjunction with the question paper and the Principal Examiner
Report for Teachers.

Cambridge will not enter into discussions about these mark schemes.

Cambridge is publishing the mark schemes for the October/November 2012 series for most IGCSE,
GCE Advanced Level and Advanced Subsidiary Level components and some Ordinary Level
components.
Page 2 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 62

1 (a) flask (1)

measuring/graduated cylinder (1) [2]

(b) (i) does not react/unreactive/not reactive enough/below hydrogen in the reactivity
series (1) [1]

(ii) magnesium/zinc/iron/aluminium (1) [1]

(c) diagram of (gas) syringe (1)

syringe labelled (1) [2]

(d) lighted splint/flame test (1)

pops (1) [2]

2 (a) straight line drawn with a ruler missing point at concentration 0.15 (1)
through origin (1) [2]

(b) 0.56/0.57/0.58 (1)

extrapolation shown (1) [2]

(d) (i) catalyst/to speed up the reaction (1) [1]

(ii) slower/owtte (1)

less surface area (1) [2]

3 (a) spatula (1) not: spoon [1]

(b) nitric/HNO3 (1) [1]

(ii) idea of ensuring constant mass (1)

reaction complete (1) [2]

(d) (i) spillage (1)

inaccurate weighing (1)
loss by spitting (1)
reaction not complete/owtte (1)
some solid left in beaker (1) [2]

Page 3 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 62

4 (a) Table of results for Experiment 1

temperature boxes completed correctly (3), –1 any incorrect

23 27 31 34 36 35 34 33 32 [3]

(b) Table of results for Experiment 2

temperature boxes completed correctly (3), –1 for each incorrect

23 28 32 35 37 38 39 38 36 [3]

(d) value from graph ,29–30 °C (1)

shown clearly (1) [2]

(e) exothermic (1) [1]

(f) (i) experiment 2/acid H (1) [1]

(ii) acid (H) is more concentrated/stronger (1) [1]

(g) room/initial temperature from table/23 °C (1)

reaction finished/owtte (1) [2]

5 (a) green (1) [1]

(b) green (1)

precipitate (1) [2]

(c) green precipitate (1) [1]

(d) no reaction/no precipitate/no change/no observation/nothing (1) [1]

(e) white (1)

precipitate (1) [2]

(i) ammonia (1) [1]

(j) transition metal/cobalt (1) ignore copper

nitrate (1) [2

Page 4 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0620 62

6 (a) test (1) e.g. add named indicator/marble chip/magnesium

result (1) e.g. ethanoic acid changes colour of indicator/ethanoic acid effervesces [2]
allow: lighted splint (1) ethanol burns (1)

(b) any 6 from:

weigh coal/equal masses/equal amounts (1)
crush (1)
heat (1)
in a fume cupboard (1)
pass through potassium manganate (1)
time to colourless (1)
repeat with other coal (1)
compare/conclusion (1) [6]

[Total: 60]

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