6497421817* Soft Clean Eraser Soft Pencil (Type B Or HB Recommended)

Cambridge International Examinations Cambridge Ordinary Level

CHEMISTRY 5070/11

Paper 1 Multiple Choice October/November 2016

1 hour Additional Materials: Multiple Choice Answer Sheet

*6497421817* Soft clean eraser Soft pencil (type B or HB recommended)

READ THESE INSTRUCTIONS FIRST

Write in soft pencil. Do not use staples, paper clips, 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. DO NOT WRITE IN ANY BARCODES.

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. Electronic calculators may be used.

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

IB16 11_5070_11/6RP © UCLES 2016 [Turn over

1 A student is given only the nucleon number of an atom.

What can be deduced about the structure of the atom?

A number of neutrons plus protons B number of neutrons only C number of protons plus electrons D number of protons only

2 Two experiments were carried out.

In experiment 1, ammonium carbonate was reacted with dilute hydrochloric acid.

In experiment 2, ammonium carbonate was heated with aqueous sodium hydroxide.

In each experiment, the gas evolved was tested with damp blue litmus paper and damp red litmus paper.

damp blue damp red damp blue damp red litmus litmus litmus litmus paper paper paper paper

dilute aqueous hydrochloric acid sodium hydroxide ammonium ammonium carbonate carbonate

heat

experiment 1 experiment 2

Which row correctly shows the colour of both the pieces of litmus paper at the end of each experiment?

experiment 1 experiment 2

A blue blue B blue red C red blue D red red

3+ 3 A paper chromatography experiment is carried out to find an Rf value for Fe (aq). The result is shown.

solvent front

Fe3+ y x

starting line

To make the spot containing Fe3+(aq) more visible, the paper is sprayed with aqueous sodium hydroxide so that a precipitate of iron(III) hydroxide forms.

3+ Under the conditions of the experiment, the Rf of Fe (aq) is given by ...... 1...... and the colour of the precipitate is ...... 2......

Which row correctly completes gaps 1 and 2?

gap 1 gap 2 x A y red-brown x B y green y C red-brown x y D green x

4 The graph gives the melting points (m.p.) of mixtures of lead and tin.

400 400

m.p. of pure lead 300 300

melting m.p. of melting point / °C pure tin point / °C 200 200

100 100

0 50 100 % tin in the mixture

The graph shows that any mixture of lead and tin must have a melting point that is

A above that of tin. B below that of lead. C below that of both tin and lead. D between that of tin and lead.

5 Some students wrote three statements about the bonding in a molecule of ammonia, NH3.

1 A nitrogen atom has three outer electrons so all outer electrons are involved in bonding. 2 A nitrogen atom has five outer electrons so two outer electrons are not involved in bonding. 3 A nitrogen atom shares electrons with each of three hydrogen atoms.

Which statements about the bonding in ammonia are correct?

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

6 Which diagram correctly shows the arrangement of the ions in solid sodium chloride?

A B

Na+ Cl – Na+ Na+

Cl – Na+ Cl – Cl –

Cl – Na+ Na+ Na+

Na+ Cl – Cl – Cl –

C D

Na+ Na+ Na+ Cl –

Cl – Cl – Cl – Na+

7 The table shows some properties of four solid elements.

Which element could be graphite?

electrical melting point

conductivity / °C

A good 97 B good 3550 C poor 113 D poor 4750

8 Which statement about chlorine atoms and chloride ions is correct?

A They are both isotopes of chlorine. B They undergo the same chemical reactions. C They have the same number of protons. D They have the same physical properties.

9 Four gases are listed.

1 CH4

2 NH3

3 CO2

4 N2

3 1 mol / dm of each of gases 1 – 4 is allowed to diffuse.

What is the order of their rate of diffusion at room temperature and pressure?

slowest fastest

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

10 Which diagram best represents the structure of a solid metal?

A B

– – + + ––+ + – + + + – + – + – + key – – + – + + ––+ + – – a negative ion – + – + – + – + – – + – + ––+ + – + + + a positive ion – – + – + + – – an electron

C D

–––– – – + + + + – –– –––– + + + + – + + + + – + + + + – – –––– – + + + + + + + + – – – –

11 A compound containing only the elements carbon and hydrogen has 80.0% by mass of carbon.

What is its empirical formula?

A C3H B CH3 C CH4 D C2H6

12 An ionic compound has the formula XY, where Y is a non-metal.

Which statement about XY is correct?

A An atom of X has lost at least one electron to form a positive ion. B Both X and Y share a pair of electrons. C Element X is also a non-metal. D XY will not conduct electricity when liquid.

3 3 13 In an experiment, 1 cm of a gaseous hydrocarbon, Z, requires 4 cm of oxygen for complete 3 combustion to give 3 cm of carbon dioxide. All gas volumes are measured at r.t.p.

Which formula represents Z?

A C2H2 B C2H4 C C3H4 D C3H8

14 Aqueous copper(II) sulfate is electrolysed using copper as the positive electrode and carbon as the negative electrode.

Which row gives correct information about this electrolysis?

positive electrode negative electrode electrolyte

A electrode dissolves copper deposited stays a constant blue colour B electrode dissolves hydrogen gas given off blue colour becomes more intense C hydrogen gas given off oxygen gas given off stays a constant blue colour D oxygen gas given off hydrogen gas given off stays a constant blue colour

15 Molten salts of four metals are electrolysed.

The ions of which metal require the smallest number of electrons for one mole of atoms to be liberated during electrolysis?

A aluminium B calcium C iron D sodium

16 Which two products are formed during photosynthesis?

A carbon dioxide and water B chlorophyll and oxygen C glucose and oxygen D glucose and water

17 A student investigates how the concentration of a reagent affects the rate of a chemical reaction.

Which piece of apparatus is essential for all rate investigations?

A balance B gas syringe C measuring cylinder D stopwatch

18 Gold is used as a catalyst in some chemical reactions.

In these reactions, gold

• helps reduce the energy costs of the reaction.

• increases the yield of the reaction.

• is unchanged at the end of the reaction.

• speeds up the rate of the reaction.

How many of these statements are correct?

A 1 B 2 C 3 D 4

19 The table shows some properties of four metal chlorides.

Which row is magnesium chloride?

colour solubility in water method of preparation

A green insoluble precipitation B green soluble metal and acid C white insoluble precipitation D white soluble metal and acid

20 A lump of element X can be cut by a knife.

During its reaction with water, X floats and melts.

What is X?

A calcium B copper C magnesium D potassium

3 21 Which row shows the pH values for 0.1 mol / dm solutions of ammonia, hydrochloric acid, sodium chloride and sodium hydroxide?

pH values

NH3 HCl NaCl NaOH

A 1 7 13 11 B 7 1 11 13 C 11 1 7 13 D 13 11 7 1

22 The diagram shows the apparatus used to extract aluminium from aluminium oxide.

carbon electrodes electrolyte

aluminium

Which statement about this process is correct?

A The electrolyte is a solid mixture of aluminium oxide and cryolite. B The electrolyte is aluminium oxide dissolved in water.

3+ – C The equation for the reaction at the positive electrode is Al + 3e → Al. D The positive carbon electrodes lose mass during the process and need regular replacement.

23 A student has five reagents.

• dilute hydrochloric acid

• dilute sulfuric acid

• dilute nitric acid

• solid calcium carbonate

• solid copper(II) carbonate

How many soluble salts can be prepared?

A 3 B 4 C 5 D 6

24 Which reaction is not a redox reaction?

A CaCO3 → CaO + CO2

B 2C + O2 → 2CO

C C + CO2 → 2CO

D Fe2O3 + 3CO → 2Fe + 3CO2

25 Some properties which make elements different from each other are listed.

1 metallic character 2 number of electron shells in an atom 3 number of protons in an atom 4 total number of electrons in an atom

Which two properties increase across a period of the Periodic Table?

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

26 Aqueous copper(II) sulfate solution is placed in an iron container and left to stand for several days.

Which statement describes what happens?

A Atmospheric oxygen reacts with the copper(II) sulfate to give black copper(II) oxide. B Some fine iron particles are formed in the solution. C The part of the container in contact with the solution is coated with copper. D The solution turns from green to blue.

27 Which equation shows a reaction that will occur at room temperature and pressure?

A Br2(aq) + 2NaCl (aq) → 2NaBr(aq) + Cl 2(aq)

B Br2(aq) + 2NaI(aq) → 2NaBr(aq) + I2(aq)

C I2(aq) + 2NaCl (aq) → 2NaI(aq) + Cl 2(aq)

D I2(aq) + 2NaBr(aq) → 2NaI(aq) + Br2(aq)

28 Attaching pieces of magnesium to underground iron pipes can protect the iron from corrosion.

Which reaction protects the iron from corrosion?

2+ – A Fe (aq) + 2e → Fe(s) B Fe(s) → Fe2+(aq) + 2e–

2+ – C Mg (aq) + 2e → Mg(s) D Mg(s) → Mg2+(aq) + 2e–

29 Which compound is used as a fertiliser?

A ammonium sulfate B barium carbonate C calcium hydroxide D lead chloride

30 In the Haber process, hydrogen and nitrogen react to form ammonia in the presence of a catalyst.

Which of the two reactants is obtained by fractional distillation and what is the catalyst used in the Haber process?

obtained by fractional catalyst distillation

A hydrogen iron B hydrogen nickel C nitrogen iron D nitrogen nickel

31 An element, Z, from Group II of the Periodic Table reacts with chlorine, an element from Group VII.

What is the formula of the ionic compound formed?

A ZCl 2 B Z2Cl C Z2Cl 7 D Z7Cl 2

32 The table shows treatments used for drinking water supplies and reasons for using those treatments.

Which row is correct?

method of water treatment reason

A chlorination removes tastes B desalination removes solids C filtration removes salt D use of carbon removes odours

33 The table shows some atmospheric pollutants and their possible effects.

Which row is not correct?

pollutant effect

A CFCs cause depletion of the ozone layer

B CO2 forms photochemical smog C CO is poisonous to humans

D NO2 forms acid rain

34 How many moles of ethanoic acid, CH3CO2H, react with one mole of magnesium?

A 1 B 2 C 3 D 4

35 With which substance will ethene react to form more than one product?

A argon B hydrogen C oxygen D steam

36 The diagram shows the structures of two hydrocarbons, X and Y.

H H

H H C H H C H H

H C C H CC

H H CH H C H H

H H

Two students make the following statements.

Student 1 Hydrocarbon X is an isomer of Y. Student 2 Hydrocarbon X is unsaturated but Y is saturated.

Which students are correct?

A both 1 and 2 B 1 only C 2 only D neither 1 nor 2

37 The diagram shows the structure of an ester.

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

H H H O C C C H

H H H

What is the name of this ester?

A butyl butanoate B butyl propanoate C propyl butanoate D propyl propanoate

38 An unsaturated hydrocarbon with six carbon atoms contains only three C=C double bonds. This hydrocarbon is reacted with excess hydrogen at a high temperature.

What is the formula of the resulting hydrocarbon?

A C6H8 B C6H10 C C6H14 D C6H16

39 Compound Q has the formula C4H10.

Which statement about compound Q is correct?

A It undergoes addition reactions with chlorine. B It has a lower boiling point than methane. C It has the same general formula as methane. D There are four C–C bonds in the molecule.

40 Hydrolysis of R, a macromolecule, gives a mixture of amino acids.

What is R?

A a fat B a nylon C a polyester D a protein

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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 2016 5070/11/O/N/16 16 2 4 – 10 86 20 18 40 36 84 54 Ar Kr 131 neon Xe He Ne Rn argon radon xenon VIII helium krypton l II – – 9 I F 85 71 35 19 17 80 53 Lr At Br 127 175 103 C Lu V 35.5 iodine fluorine lutetium chlorine astatine bromine lawrencium I 6 – – – 8 S 70 84 16 16 32 34 79 52 O V 11 128 173 102 Te Lv sulfur Se Po Yb No oxygen tellurium selenium polonium nobelium ytterbium livermorium 7 – V P 69 83 14 15 31 33 75 51 N Bi 122 209 169 101 As Sb Md Tm arsenic thulium bismuth nitrogen antimony phosphorus mendelevium l 9 4 – – 6 tin 68 12 14 28 32 73 50 82 C IV Si F lead 11 11 Er 207 167 100 Sn Pb Ge silicon Fm erbium carbon fermium flerovium germanium l l 5 n 5 – 11 B 99 81 27 31 70 49 13 67 III T A 11 I 204 165 Es Ho boron Ga indium gallium thallium holmium aluminium einsteinium 2 2 – – 80 48 30 65 66 98 zinc 11 11 201 Cf 163 Zn Dy Cd Hg Cn mercury cadmium californium dysprosium copernicium – – 29 65 64 47 79 97 111 gold 108 197 159 silver Tb Bk Ag Au Cu Rg copper terbium berkelium roentgenium 0 – – 78 96 59 46 28 64 Ni Pt 11 106 195 157 Ds Pd nickel Gd curium Cm platinum palladium gadolinium darmstadtium .t.p.) ble of Elements a Group r – – 77 95 27 63 59 45 I 103 192 109 152 Mt Eu Co Rh cobalt iridium Am rhodium europium americium meitnerium 1 1 – – 76 94 56 44 62 26 H iron 101 190 108 150 Fe Hs Pu Os Ru Sm osmium hassium hydrogen plutonium samarium ruthenium The Periodic T – – – – 61 93 25 75 55 43 Tc 186 107 Bh Np Re Mn Pm rhenium bohrium neptunium technetium manganese promethium – 60 92 52 42 96 74 24 U W 144 238 184 106 Cr Sg Nd Mo uranium tungsten chromium neodymium seaborgium molybdenum at room temperature and pressure (r 3 dm

– V 23 51 41 93 73 59 91 Pr 181 105 141 231 Ta Pa name Nb Db Key niobium tantalum dubnium vanadium protactinium praseodymium atomic number relative atomic mass atomic symbol – 58 90 48 40 91 72 22 Ti Zr Hf Rf 178 104 140 232 Th Ce cerium thorium titanium hafnium zirconium rutherfordium – 89 57 Y 45 39 89 21 139 La Ac Sc yttrium 57–71 actinium actinoids 89–103 scandium lanthanum lanthanoids I 4 9 – 88 24 40 88 56 12 20 38 Sr 137 Be Ba Ca Ra Mg barium radium calcium beryllium strontium magnesium II 3 7 – 11 K 19 37 55 23 39 85 87 Li Fr 133 Cs Na Rb lithium sodium caesium francium rubidium potassium actinoids The volume of one mole of any gas is 24 lanthanoids

Cambridge International Examinations Cambridge Ordinary Level

CHEMISTRY 5070/12

Paper 1 Multiple Choice October/November 2016

1 hour Additional Materials: Multiple Choice Answer Sheet

*5229043977 Soft clean eraser Soft pencil (type B or HB recommended)

READ THESE INSTRUCTIONS FIRST

Write in soft pencil. Do not use staples, paper clips, 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. DO NOT WRITE IN ANY BARCODES.

Read the instructions on the Answer Sheet very carefully.

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

IB16 11_5070_12/5RP © UCLES 2016 [Turn over

1 When measured under the same conditions, which gas diffuses at the same rate as nitrogen?

A ammonia, NH3 B carbon monoxide, CO

C ethane, C2H6

D oxygen, O2

2 When calcium carbonate is added to dilute hydrochloric acid, carbon dioxide gas is released.

Three sets of apparatus are shown.

tap cotton wool funnel

CaCO3(s) + HCl (aq)

CaCO (s) 0100.02 3 + HCl (aq) gas syringe

1 2 thistle funnel

measuring cylinder

CaCO3(s) + HCl (aq)

water 3

Which sets of apparatus are suitable, together with a stopwatch, for following the rate of this reaction?

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

3 Which statement is correct?

A Carbon monoxide reduces sodium oxide to sodium. B During the electrolysis of copper(II) sulfate solution, hydrogen is liberated at the positive electrode. C Recycling aluminium conserves the Earth’s finite supply of haematite. D Iron oxide is reduced to iron in the blast furnace.

4 Benzene and cyclohexane are both flammable liquids. They are able to mix with each other without separating into two layers. They have very similar boiling points. It is difficult to separate a mixture of these two liquids by fractional distillation.

Why is it difficult to separate a mixture of benzene and cyclohexane by fractional distillation?

A They are both flammable. B They are both liquids. C They have very similar boiling points. D They mix with each other completely.

5 The graph gives the melting points (m.p.) of mixtures of lead and tin.

400 400

m.p. of pure lead 300 300

melting m.p. of melting point / °C pure tin point / °C 200 200

100 100

0 50 100 % tin in the mixture

The graph shows that any mixture of lead and tin must have a melting point that is

A above that of tin. B below that of lead. C below that of both tin and lead. D between that of tin and lead.

6 Which statement about chlorine atoms and chloride ions is correct?

A They are both isotopes of chlorine. B They undergo the same chemical reactions. C They have the same number of protons. D They have the same physical properties.

7 When substance Q melts, only weak forces of attraction between its molecules are overcome.

Which row correctly describes Q?

electrical conduction melting point / °C of solid Q

A 44 non-conductor B 98 conductor C 660 conductor D 714 non-conductor

8 A solution containing lead(II) ions is added to a solution containing iodide ions. A yellow precipitate is formed.

What is the equation for the reaction that occurs?

+ – A Pb + I → PbI

+ – B Pb + 2I → PbI2 C Pb2+ + I– → PbI

2+ – D Pb + 2I → PbI2

9 Buckminsterfullerene has the chemical formula C60.

carbon atom

buckminsterfullerene

How is the structure of buckminsterfullerene best described?

A a covalent compound B an ionic compound C a polymer D molecular

10 Which diagram correctly shows the arrangement of the ions in solid sodium chloride?

A B

Na+ Cl – Na+ Na+

Cl – Na+ Cl – Cl –

Cl – Na+ Na+ Na+

Na+ Cl – Cl – Cl –

C D

Na+ Na+ Na+ Cl –

Cl – Cl – Cl – Na+

11 Aqueous sodium hydroxide is added to a sample of a colourless solution. Aqueous ammonia is added to a separate sample of the colourless solution.

In both cases a white precipitate forms which is soluble in excess reagent.

Which positive ion is present in the solution?

A aluminium B calcium

C copper(II) D zinc

3 3 12 In an experiment, 1 cm of a gaseous hydrocarbon, Z, requires 4 cm of oxygen for complete 3 combustion to give 3 cm of carbon dioxide. All gas volumes are measured at r.t.p.

Which formula represents Z?

A C2H2 B C2H4 C C3H4 D C3H8

13 Which is the best conductor of electricity?

A diamond B magnesium C pure ethanoic acid D solid sodium chloride

14 Molten salts of four metals are electrolysed.

The ions of which metal require the smallest number of electrons for one mole of atoms to be liberated during electrolysis?

A aluminium B calcium C iron D sodium

15 An endothermic reaction has an activation energy of x.

Which energy profile diagram is correct for this reaction?

A B

x products reactants energy energy x

reactants products

reaction pathway reaction pathway

C D

x x reactants products energy energy

products reactants

reaction pathway reaction pathway

16 The following statements refer to the use of catalysts in chemical reactions.

1 A catalyst increases the activation energy of a reaction. 2 A catalyst increases the rate of a reaction. 3 A catalyst increases the yield of a reaction.

Which statements are correct?

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

17 In two experiments, 1 and 2, an excess of powdered calcium carbonate was reacted in a flask with dilute hydrochloric acid.

In experiment 1, the carbon dioxide evolved was collected and the volume of gas measured at regular intervals.

In experiment 2, the mass of the flask and its contents was measured at regular intervals.

The results of both experiments were plotted on graphs.

W X Y Z

volume volume mass mass

0 0 0 0 0time 000 time time time

experiment 1 experiment 1 experiment 2 experiment 2

Which graphs correctly show the results of these two experiments?

experiment 1 experiment 2

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

18 Iron(II) ions react with chlorine.

2+ 3+ – 2Fe (aq) + Cl 2(g) → 2Fe (aq) + 2Cl (aq)

Which statement about this reaction is correct?

A Chlorine is reduced by iron(II) ions. B Chlorine is the reducing agent.

C Iron(II) ions are reduced by chlorine.

D Iron(II) ions are the oxidising agent.

19 When water is liquid, it ionises slightly.

+ – H2O(l) H (aq) + OH (aq)

The forward reaction is endothermic.

When the temperature of water is increased, which change(s) take place?

1 The water becomes acidic. 2 The water becomes alkaline. 3 More water molecules form ions.

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

20 The table shows some properties of four metal chlorides.

Which row is magnesium chloride?

colour solubility in water method of preparation

A green insoluble precipitation B green soluble metal and acid C white insoluble precipitation D white soluble metal and acid

21 Which statement about the uses of metals is not correct?

A Aluminium is used for making food containers and electrical cables. B Copper is used for making brass. C Iron is used as a catalyst in the contact process. D Nickel is used as a catalyst in the hydrogenation of alkenes.

22 A lump of element X can be cut by a knife.

During its reaction with water, X floats and melts.

What is X?

A calcium B copper C magnesium D potassium

23 Which row is a transition element?

melting density 3 point / °C in g / cm

A 44 1.82 B 181 0.53 C 271 9.75 D 1244 7.20

24 Element Z combines with sodium to form the compound Na2Z.

The positions of four elements are shown on the outline of part of the Periodic Table.

Which is element Z?

AB C

25 The table shows the observations made when an aqueous solution of salt Z has different reagents added to it.

reagent(s) added observation

aqueous sodium hydroxide green precipitate formed dilute nitric acid white precipitate formed then aqueous barium nitrate

What is Z?

A copper(II) chloride

B copper(II) sulfate

C iron(II) chloride

D iron(II) sulfate

26 The diagram shows the apparatus used to extract aluminium from aluminium oxide.

carbon electrodes electrolyte

aluminium

Which statement about this process is correct?

A The electrolyte is a solid mixture of aluminium oxide and cryolite. B The electrolyte is aluminium oxide dissolved in water.

3+ – C The equation for the reaction at the positive electrode is Al + 3e → Al. D The positive carbon electrodes lose mass during the process and need regular replacement.

27 Which reaction is not a redox reaction?

A CaCO3 → CaO + CO2

B 2C + O2 → 2CO

C C + CO2 → 2CO

D Fe2O3 + 3CO → 2Fe + 3CO2

28 Aqueous copper(II) sulfate solution is placed in an iron container and left to stand for several days.

Which statement describes what happens?

29 In the manufacture of paper, sulfur dioxide is used to remove the yellow colour from the wood pulp.

Which term can be used to describe sulfur dioxide in this process?

A a bleach B a catalyst C an oxidising agent D a solvent

30 Which statement about the uses of gases is not correct?

A Helium is used in balloons because it is unreactive and less dense than air. B Hydrogen is used in an addition reaction with saturated vegetable oils to form margarine. C Nitrogen from the air is used in the manufacture of ammonia. D Oxygen is used in making steel and welding.

31 Electrical energy can be generated using simple cells as shown.

metals

electrolyte

Which pair of metals, when used as electrodes, will give the largest reading on the voltmeter, V?

A lead and sodium B magnesium and copper C potassium and silver D sodium and potassium

32 When reacted with an excess of dilute hydrochloric acid, 0.002 moles of a metal M liberated 3 48 cm of hydrogen measured at r.t.p.

Which equation is correct for this reaction?

+ + A 2M + 2H → 2M + H2

+ + B M + H → M + H

+ 2+ C M + 2H → M + H2

+ 2+ D M + 2H → M + 2H

33 The diagram shows a section of a polymer.

H C2H5 H C2H5 H C2H5

C C C CCC

H H H H H H

Which alkene is used to make this polymer?

A CH3CH=CH2

B CH3CH2CH=CH2

C CH3CH2CH=CHCH3

D CH3CH=CHCH3

34 The table shows some atmospheric pollutants and their possible effects.

Which row is not correct?

pollutant effect

A CFCs cause depletion of the ozone layer

B CO2 forms photochemical smog C CO is poisonous to humans

D NO2 forms acid rain

35 Which compound is the most viscous and the least flammable?

A C6H14 B C8H18 C C10H22 D C12H26

36 How many moles of ethanoic acid, CH3CO2H, react with one mole of magnesium?

A 1 B 2 C 3 D 4

37 With which substance will ethene react to form more than one product?

A argon B hydrogen C oxygen D steam

38 Which statement about isomers of a compound is always correct?

A They have different empirical formulae. B They have different relative molecular masses. C They have only carbon and hydrogen in their molecules. D They have the same molecular formula.

39 How many of the structures show an unsaturated hydrocarbon molecule?

O CO CH3 CH2 CH2 CH3 CH3 CH CH2 CH3 C

O H

A 1 B 2 C 3 D 4

40 Which type of polymer is made by reacting amino acids together?

A an addition polymer B a carbohydrate C a polyamide D a polyester

BLANK PAGE

© UCLES 2016 5070/12/O/N/16 16 2 4 – 10 86 20 18 40 36 84 54 Ar Kr 131 neon Xe He Ne Rn argon radon xenon helium krypton l – – 9 I F 85 71 35 19 17 80 53 Lr At Br 127 175 103 C Lu 35.5 iodine fluorine lutetium chlorine astatine bromine lawrencium – – – 8 S 70 84 16 16 32 34 79 52 O 116 128 173 102 Te Lv sulfur Se Po Yb No oxygen tellurium selenium polonium nobelium ytterbium livermorium 7 – P 69 83 14 15 31 33 75 51 N Bi 122 209 169 101 As Sb Md Tm arsenic thulium bismuth nitrogen antimony phosphorus mendelevium l 6 – – tin 68 12 14 28 32 73 50 82 C Si F lead 119 114 Er 207 167 100 Sn Pb Ge silicon Fm erbium carbon fermium flerovium germanium l l n 5 – 11 B 99 81 27 31 70 49 13 67 III IV V VI VII VIII T A 115 I 204 165 Es Ho boron Ga indium gallium thallium holmium aluminium einsteinium – – 80 48 30 65 66 98 zinc 112 112 201 Cf 163 Zn Dy Cd Hg Cn mercury cadmium californium dysprosium copernicium – – 64 47 29 65 79 97 111 gold 108 197 159 silver Tb Bk Ag Au Cu Rg copper terbium berkelium roentgenium – – 78 96 59 46 28 64 Ni Pt 110 106 195 157 Ds Pd nickel Gd curium Cm platinum palladium gadolinium darmstadtium Group r – – 77 95 27 63 59 45 I 103 192 109 152 Mt Eu Co Rh cobalt iridium Am rhodium europium americium meitnerium 1 1 – – 76 94 56 44 62 26 H iron 101 190 108 150 Fe Hs Pu Os Ru Sm osmium hassium hydrogen plutonium samarium ruthenium The Periodic Table of Elements The Periodic Table – – – – 61 93 75 55 43 25 Tc 186 107 Bh Np Re Mn Pm rhenium bohrium neptunium technetium manganese promethium – 60 92 24 52 42 96 74 U W 144 238 184 106 Cr Sg Nd Mo uranium tungsten chromium neodymium seaborgium molybdenum at room temperature and pressure (r.t.p.) 3 dm

– V 23 51 41 93 73 59 91 Pr 181 105 141 231 Ta Pa name Nb Db Key niobium tantalum dubnium vanadium protactinium praseodymium atomic number relative atomic mass atomic symbol – 58 90 48 40 91 72 22 Ti Zr Hf Rf 178 104 140 232 Th Ce cerium thorium titanium hafnium zirconium rutherfordium – 89 57 Y 45 39 89 21 139 La Ac Sc yttrium 57–71 actinium actinoids 89–103 scandium lanthanum lanthanoids 4 9 – 88 24 40 88 56 12 20 38 Sr 137 Be Ba Ca Ra Mg barium radium calcium beryllium strontium magnesium III 3 7 – 11 K 19 37 55 23 39 85 87 Li Fr 133 Cs Na Rb lithium sodium caesium francium rubidium potassium actinoids The volume of one mole any gas is 24 lanthanoids

CHEMISTRY 5070/21 Paper 2 Theory October/November 2016 1 hour 30 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 an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES.

Section A Answer all questions. Write your answers in the spaces provided in the Question Paper.

Section B Answer any three questions. Write your answers in the spaces provided in the Question Paper.

Electronic calculators may be used. You may lose marks if you do not show your working or if you do not use appropriate units. A copy of the Periodic Table is printed on page 20.

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.

This document consists of 18 printed pages and 2 blank pages.

DC (LEG/SG) 107872/3 © UCLES 2016 [Turn over 2

Section A

Answer all the questions in this section in the spaces provided.

The total mark for this section is 45.

A1 Choose from the following compounds to answer the questions below.

Ba(NO3)2

CaCO3 CaO

CH4

C3H8

Fe2O3

KMnO4

NaNO3 NO

SO2

V2O5

Zn(NO3)2

Each of these compounds can be used once, more than once or not at all.

Which compound

(a) is an atmospheric pollutant formed by lightning activity,

...... [1]

(b) is the main constituent of natural gas,

...... [1]

(c) dissolves in water to form an aqueous solution which gives a white precipitate on addition of aqueous sodium sulfate,

...... [1]

(d) is a catalyst in the contact process for the manufacture of sulfuric acid,

...... [1]

(e) is a product of the thermal decomposition of limestone?

...... [1]

[Total: 5]

A2 Sulfuric acid is a strong acid.

(a) (i) What is meant by the term strong acid ?

...... [1]

(ii) Describe how you could measure the pH of dilute sulfuric acid.

......

...... [1]

(b) Many plants cannot grow in soils which are too acidic.

Describe and explain how soils which are too acidic can be treated to reduce the acidity.

......

...... [2]

rate of uptake of potassium ions

23 45678910 soil pH

Describe how the rate of uptake of potassium ions varies with soil pH.

......

...... [1]

[Total: 5]

A3 The alcohols are a homologous series with the general formula CnH2n+1OH.

(a) Deduce the molecular formula of the alcohol having eight carbon atoms.

...... [1]

(b) The table shows some information about different alcohols.

alcohol formula melting point boiling point density / °C / °C in g / cm3

ethanol C2H5OH –117 79 0.789

propanol C3H7OH –126 98 0.804

butanol C4H9OH –89 117

pentanol C5H11OH –79 138 0.815

hexanol C6H13OH –47 158 0.820

(i) Describe how the boiling point changes with the number of carbon atoms in the alcohol.

...... [1]

(ii) Estimate the density, in g / cm3, of butanol.

...... [1]

(iii) What is the physical state of pentanol at room temperature and pressure? Explain your answer.

......

...... [1]

Explain your answer.

......

...... [2]

(d) Construct the equation for the complete combustion of propanol.

...... [2]

(e) Propanol can be oxidised to propanoic acid.

(i) Suggest the oxidising agent and describe the conditions used for this reaction.

......

...... [2]

(ii) Draw the structure of propanoic acid, showing all the atoms and all the bonds.

[1]

[Total: 11]

2– A4 Peroxodisulfate ions, S2O8 , react with iodide ions in aqueous solution.

2– – 2– S2O8 (aq) + 2I (aq) 2SO4 (aq) + I2(aq)

The table shows how the relative rate of this reaction changes when different concentrations of peroxodisulfate ions and iodide ions are used.

concentration of S O 2– concentration of I– relative rate experiment 2 8 in mol / dm3 in mol / dm3 of reaction 1 0.008 0.02 1.7 2 0.016 0.02 3.3 3 0.032 0.02 6.8 4 0.008 0.04 3.4 5 0.008 0.08 6.9

(a) Use the information in the table to describe how increasing the concentration of each of these ions affects the relative rate of reaction.

peroxodisulfate ions ......

......

iodide ions ......

...... [2]

(b) Iron(III) ions, Fe3+, catalyse this reaction.

Explain how catalysts increase the rate of a reaction.

......

...... [1]

– 3+ 2+ 2I (aq) + 2Fe (aq) I2(aq) + 2Fe (aq)

(i) Explain how iron(III) ions are acting as an oxidising agent in this reaction.

......

...... [1]

(ii) What colour change is observed when this reaction happens?

...... [1]

(iii) Describe a test for iron(III) ions.

test ......

observation ...... [2]

(d) Iron(II) ions react with peroxodisulfate ions. The products are iron(III) ions and sulfate ions.

Construct the equation for this reaction.

...... [1]

[Total: 8]

A5 Potassium chlorate, KCl O3, decomposes to form potassium chloride and oxygen.

2KCl O3(s) 2KCl (s) + 3O2(g)

(a) Calculate the percentage by mass of oxygen in potassium chlorate.

[2]

(b) Calculate the maximum volume of oxygen formed at room temperature and pressure when 12.25 g of potassium chlorate is completely decomposed.

[3]

(i) Explain in terms of gain and loss of electrons, how potassium ions and chloride ions are formed when potassium reacts with chlorine.

......

...... [3]

(ii) Predict two physical properties of potassium chloride.

......

...... [2]

[Total: 10]

A6 Dry air contains nitrogen, oxygen, argon and other gases.

(a) State the percentage compositions by volume of nitrogen and oxygen present in dry air.

nitrogen ...... %

oxygen ...... % [1]

(b) The formula for oxygen gas is O2.

(i) Draw a ‘dot-and-cross’ diagram of an oxygen molecule.

Show only the outer shell electrons.

[1]

(ii) What is the formula of argon gas?

...... [1]

(c) Titanium is extracted from titanium(IV) chloride by reduction with molten sodium in an argon atmosphere and not in air.

Suggest why this reaction is carried out in an argon atmosphere and not in air.

......

...... [2]

(d) State one other use of argon.

...... [1]

[Total: 6]

Section B

Answer three questions from this section in the spaces provided.

The total mark for this section is 30.

B7 Ethenyl ethanoate, CH3CO2CH=CH2, is manufactured by passing a mixture of ethanoic acid, ethene and oxygen over a catalyst at 200 °C.

CH3CO2H + CH2=CH2 + ½O2 CH3CO2CH=CH2 + H2O

The reaction is exothermic.

(a) Draw an energy profile diagram for this reaction on the axes shown.

On your diagram label • the reactants and products, • the enthalpy change for the reaction, • the activation energy.

energy

reaction pathway

[3]

(b) Ethenyl ethanoate is an unsaturated compound.

Describe a chemical test for an unsaturated compound.

test ......

observation ...... [2]

Copper reacts with concentrated nitric acid.

Complete the equation for this reaction.

Cu + ….HNO3 Cu(NO3)2 + ….H2O + ….NO2 [1]

(d) The structure of ethenyl ethanoate is shown.

COCH3

O H

C C

H H

Draw the structure of the addition polymer formed from ethenyl ethanoate.

[2]

(e) State two pollution problems caused by non-biodegradable plastics.

......

...... [2]

[Total: 10]

B8 Ethanol can be manufactured by reacting ethene with steam in a closed reaction vessel.

C2H4(g) + H2O(g) C2H5OH(g)

The reaction is exothermic.

(a) State two conditions for this reaction.

......

...... [2]

(b) The graph shows the percentage yield of ethanol at different temperatures.

% yield 30 of ethanol 20

10 100 200 300 400 temperature / °C

(i) Describe how, and explain why, the percentage yield changes with temperature.

......

...... [3]

(ii) Suggest why the reaction is carried out at 300 °C and not at 200 °C.

......

...... [2]

......

...... [2]

(d) Ethanol reacts with methanoic acid, HCO2H, to form ethyl methanoate and water.

Construct the equation for this reaction.

...... [1]

[Total: 10]

B9 Tin and silver are metals.

(a) State two properties which are characteristic of most metals.

......

...... [2]

(b) Draw a labelled diagram to show how a tin rod can be electroplated with silver.

[3]

Deduce the empirical formula of this chloride of tin.

empirical formula ...... [2]

(d) Tin(II) oxide reacts with oxygen to form tin(IV) oxide.

2SnO + O2 2SnO2 tin(II) oxide tin(IV) oxide

When a sample of 13.5 g of tin(II) oxide is reacted with oxygen, 12.7 g of tin(IV) oxide is formed.

Calculate the percentage yield of tin(IV) oxide.

...... % [3]

[Total: 10]

B10 A student prepared some crystals of hydrated lithium nitrate by reacting aqueous lithium hydroxide with dilute nitric acid.

LiOH + HNO3 + 2H2O LiNO3.3H2O

(a) Explain how you would carry out this procedure to obtain pure dry crystals of hydrated lithium nitrate.

......

...... [4]

(b) The student used 20.0 cm3 of 0.500 mol / dm3 of lithium hydroxide to prepare the crystals.

Calculate the maximum mass of hydrated lithium nitrate crystals that could be made.

...... g [3]

2LiNO3.3H2O(s) Li2O(s) + 2NO2(g) + ½O2(g) + 6H2O(l)

What is observed during this reaction?

...... [1]

(d) Explain why lithium oxide conducts electricity when molten.

...... [1]

(e) Predict the products of electrolysis of molten lithium oxide at

the anode (positive electrode), ......

the cathode (negative electrode)...... [1]

[Total: 10]

BLANK PAGE

© UCLES 2016 5070/21/O/N/16 20 4 – 2 86 10 20 18 40 36 84 54 Ar Kr 131 neon Xe He Ne Rn argon radon xenon helium krypton l – – 9 I F 85 35 19 17 80 53 71 Lr At Br 127 175 103 C Lu 35.5 iodine fluorine lutetium chlorine astatine bromine lawrencium – – – 8 S 70 16 16 32 34 79 52 84 O 116 128 173 102 Te Lv sulfur Se Po Yb No oxygen tellurium selenium polonium nobelium ytterbium livermorium 7 – P 83 14 15 31 33 75 51 69 N Bi 122 209 169 101 As Sb Md Tm arsenic thulium bismuth nitrogen antimony phosphorus mendelevium l – – 6 tin 12 14 28 32 73 50 68 82 C Si F lead 119 114 Er 207 167 100 Sn Pb Ge silicon Fm erbium carbon fermium flerovium germanium l l n – 5 11 B 99 13 81 27 31 70 49 67 III IV V VI VII VIII T A 115 I 204 165 Es Ho boron Ga indium gallium thallium holmium aluminium einsteinium – – 48 80 65 30 98 66 zinc 112 112 201 Cf 163 Zn Dy Cd Hg Cn mercury cadmium californium dysprosium copernicium – – 64 47 29 65 79 97 111 gold 108 197 159 silver Tb Bk Ag Au Cu Rg copper terbium berkelium roentgenium – – 59 46 78 96 28 64 Ni Pt 110 106 195 157 Ds Pd nickel Gd curium Cm platinum palladium gadolinium darmstadtium Group r – – 59 45 77 95 27 63 I 103 192 109 152 Mt Eu Co Rh cobalt iridium Am rhodium europium americium meitnerium 1 1 – – 76 94 56 44 62 26 H iron 101 190 108 150 Fe Hs Pu Os Ru Sm osmium hassium hydrogen plutonium samarium ruthenium The Periodic Table of Elements The Periodic Table – – – – 93 61 75 55 43 25 Tc 186 107 Bh Np Re Mn Pm rhenium bohrium neptunium technetium manganese promethium – 60 92 52 42 96 74 24 U W 144 238 184 106 Cr Sg Nd Mo uranium tungsten chromium neodymium seaborgium molybdenum at room temperature and pressure (r.t.p.) 3 dm

– V 51 41 93 73 23 59 91 Pr 181 105 141 231 Ta Pa name Nb Db Key niobium tantalum dubnium vanadium protactinium praseodymium atomic number relative atomic mass atomic symbol – 22 90 48 40 91 72 58 Ti Zr Hf Rf 178 104 140 232 Th Ce cerium thorium titanium hafnium zirconium rutherfordium – 89 57 Y 21 45 39 89 139 La Ac Sc yttrium 57–71 actinium actinoids 89–103 scandium lanthanum lanthanoids 9 – 4 24 40 88 88 56 12 20 38 Sr 137 Be Ba Ca Ra Mg barium radium calcium beryllium strontium magnesium III 3 7 – 11 K 19 37 55 87 23 39 85 Li Fr 133 Cs Na Rb lithium sodium caesium francium rubidium potassium actinoids The volume of one mole any gas is 24 lanthanoids

CHEMISTRY 5070/22 Paper 2 Theory October/November 2016 1 hour 30 minutes Candidates answer on the Question Paper. No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Section A Answer all questions. Write your answers in the spaces provided in the Question Paper.

Section B Answer any three questions. Write your answers in the spaces provided in the Question Paper.

Electronic calculators may be used. You may lose marks if you do not show your working or if you do not use appropriate units. A copy of the Periodic Table is printed on page 20.

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.

This document consists of 18 printed pages and 2 blank pages.

DC (LEG/SG) 107871/4 © UCLES 2016 [Turn over 2

Section A

Answer all the questions in this section in the spaces provided.

The total mark for this section is 45.

A1 Choose from the following compounds to answer the questions below.

BaCl 2

C2H4

C3H4

C3H8 CO

CO2

K2SO4

Na3PO4

SO2

ZnSO4

Each of these compounds can be used once, more than once or not at all.

Give a compound which

(a) is an acidic atmospheric pollutant from volcanic eruptions,

...... [1]

(b) is a saturated hydrocarbon,

...... [1]

(c) dissolves in water to form an aqueous solution which gives a white precipitate on addition of aqueous sodium hydroxide,

...... [1]

(d) reduces iron(III) oxide to iron in the blast furnace,

...... [1]

(e) contributes to the process of eutrophication.

...... [1]

[Total: 5]

A2 Farmers add fertilisers such as ammonium sulfate to the soil to increase the rate of plant growth.

(a) Write the formulae of the ions present in ammonium sulfate.

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

(b) Describe a test for ammonium ions.

test ......

observation ...... [2]

Write the ionic equation for the reaction of aqueous ammonia with sulfuric acid.

...... [1]

[Total: 5]

A3 The alkanes are a homologous series of hydrocarbons.

(a) State two properties of a homologous series.

......

...... [2]

(b) Draw the structures of the branched and unbranched alkanes having four carbon atoms.

Show all the atoms and all the bonds.

[2]

(c) The graph shows how the melting points of the first nine unbranched alkanes vary with the number of carbon atoms per molecule.

–50 melting point / °C –100

–150

–200 1 2 3 4 5 6 7 8 9 10 number of carbon atoms per molecule

(i) Describe how the melting points of these alkanes change with the number of carbon atoms.

......

...... [2]

(ii) Use the graph to estimate the melting point of the unbranched alkane which has ten carbon atoms.

...... °C [1]

(d) (i) Construct the equation for the complete combustion of pentane, C5H12.

...... [2]

(ii) Name the products of the incomplete combustion of pentane and explain why the incomplete combustion of hydrocarbons is hazardous to health.

......

...... [2]

[Total: 11]

I A4 Propanone, CH3COCH3, reacts with iodine, 2, to form colourless products. I I I CH3COCH3 + 2 CH3COCH2 + H

The reaction is catalysed by hydrochloric acid.

The table shows how the relative rate of this reaction changes when different concentrations of propanone, iodine and hydrochloric acid are used.

experiment concentration of concentration of relative rate concentration of I CH COCH 2 hydrochloric acid of reaction 3 3 in mol / dm3 in mol / dm3 in mol / dm3 1 0.025 0.024 0.12 5.1 2 0.050 0.024 0.12 10.2 3 0.050 0.024 0.06 5.1 4 0.050 0.012 0.06 5.1

(a) Describe how increasing the concentration of each of these substances affects the relative rate of reaction.

propanone ......

iodine ......

hydrochloric acid ...... [3]

(b) Increasing the temperature increases the rate of this reaction.

Explain why, in terms of kinetic particle theory.

......

...... [2]

What are isotopes?

......

...... [1]

(d) Astatine, At, is a halogen.

Aqueous iodine reacts with aqueous astatide ions, At–, to produce astatine.

Construct the ionic equation for this reaction.

...... [1]

(e) Aqueous hydrogen iodide reduces hydrogen peroxide to water.

+ I– I H2O2(aq) + 2H (aq) + 2 (aq) 2H2O(l) + 2(aq)

Explain how iodide ions act as a reducing agent in this reaction.

......

...... [1]

[Total: 8]

A5 Nickel carbonyl, Ni(CO)4, reacts with hydrogen iodide. I I Ni(CO)4(l) + 2H (g) Ni 2(s) + H2(g) + 4CO(g)

(a) Calculate the percentage by mass of nickel in nickel carbonyl.

...... % [2]

(b) Calculate the maximum volume of gas formed at room temperature and pressure when 1.71 g of nickel carbonyl reacts completely with hydrogen iodide.

maximum volume of gas formed ...... [3]

OC Ni CO

Predict two physical properties of nickel carbonyl.

......

...... [2]

(d) The proton numbers and accurate relative atomic masses of cobalt and nickel are shown in the table.

cobalt nickel proton number 27 28 relative atomic mass 58.9 58.7

Suggest why cobalt has a higher relative atomic mass than nickel.

......

...... [2]

(e) An aqueous solution of hydrogen iodide is a strong acid.

What is meant by the term strong acid ?

......

...... [1]

[Total: 10]

A6 Sodium and rubidium are alkali metals.

(a) Explain how metals conduct electricity.

...... [1]

(b) State two trends in the properties of the alkali metals.

......

...... [2]

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

(d) Titanium is extracted from titanium(IV) chloride by reduction with molten sodium.

l l TiC 4 + 4Na 4NaC + Ti

Suggest why sodium reduces titanium(IV) chloride.

...... [1]

[Total: 6]

BLANK PAGE

Section B

Answer three questions from this section in the spaces provided.

The total mark for this section is 30.

B7 In the contact process, sulfur trioxide is made by the catalytic oxidation of sulfur dioxide. In a closed container the following equilibrium is set up.

2SO2(g) + O2(g) 2SO3(g)

The reaction is exothermic.

(a) Name the catalyst used in this reaction.

...... [1]

(b) Draw a ‘dot-and-cross’ diagram of an oxygen molecule.

Show only the outer shell electrons.

[1]

100

90 % yield 85

75 100 200 300 400 500 600 temperature / °C

(i) Describe how, and explain why, the percentage yield of sulfur trioxide changes with temperature.

......

...... [3]

(ii) Suggest why the reaction is carried out at 450 °C and not at 250 °C.

......

...... [2]

(d) Describe how, and explain why, the position of equilibrium changes when the pressure increases.

......

...... [2]

(e) Sulfur trioxide oxidises hydrogen bromide to form sulfur dioxide, bromine and water.

Construct the equation for this reaction.

...... [1]

[Total: 10]

B8 Propenenitrile, CH2=CHCN, is made by passing a mixture of propene, ammonia and oxygen over a catalyst at 450 °C.

CH3CH=CH2 + NH3 + 1½O2 CH2=CHCN + 3H2O

The reaction is exothermic.

(a) Draw an energy profile diagram for this reaction on the axes shown.

On your diagram label • the reactants and products, • the enthalpy change for the reaction, • the activation energy.

energy

reaction pathway

[3]

(b) Propenenitrile decolourises aqueous bromine.

Explain why.

......

...... [1]

H CN

C C

H H

Draw the structure of the addition polymer formed from propenenitrile.

[2]

(d) The catalyst used in the reaction to make propenenitrile is molybdenum. Molybdenum is a transition element.

(i) State two physical properties of molybdenum.

......

...... [2]

(ii) Molybdenum reacts with chlorine at room temperature to form molybdenum(VI) chloride, l VI MoC 6. Molybdenum( ) chloride has a melting point of 254 °C.

Construct an equation for this reaction, including state symbols.

...... [2]

[Total: 10]

B9 Both copper and magnesium are metals.

(a) Explain why magnesium reacts with hydrochloric acid but copper does not.

...... [1]

(b) Brass is an alloy of copper and zinc. The table shows how the composition of brass influences its relative strength.

composition of brass relative strength % copper % zinc 90 10 2.6 80 20 3.0 70 30 3.3 60 40 3.6

How does the composition of brass affect its strength?

......

...... [1]

You may include a labelled diagram in your answer.

......

...... [3]

(d) Draw a labelled diagram to show how a steel rod can be electroplated with copper.

[3]

(e) A 11.09 g sample of an oxide of copper contains 9.86 g of copper.

Deduce the empirical formula of this oxide of copper.

empirical formula ...... [2]

[Total: 10]

B10 A student prepared some crystals of hydrated copper(II) sulfate by reacting excess insoluble copper(II) oxide with dilute sulfuric acid.

CuO + H2SO4 + 4H2O CuSO4.5H2O

(a) Describe how you would obtain pure dry crystals of hydrated copper(II) sulfate from the reaction mixture.

......

...... [3]

(b) The student used 15.0 cm3 of 2.00 mol / dm3 sulfuric acid to prepare the crystals.

Calculate the maximum mass of hydrated copper(II) sulfate crystals that could be made.

...... g [3]

What is observed as the aqueous ammonia is added?

......

...... [2]

(d) An aqueous solution of copper(II) sulfate is electrolysed using inert electrodes.

Predict the products of this electrolysis at

the anode (positive electrode), ......

the cathode (negative electrode)...... [2]

[Total: 10] © UCLES 2016 5070/22/O/N/16 19

BLANK PAGE

© UCLES 2016 5070/22/O/N/16 20 4 – 2 20 18 40 36 84 54 86 10 Ar Kr 131 neon Xe He Ne Rn argon radon xenon VIII helium krypton e l II – – 9 I F 35 19 17 80 53 85 71 Lr At Br 127 175 103 C Lu 35.5 iodine fluorine lutetium chlorine astatine bromin lawrencium IV 6 8 – – – S 16 16 32 34 79 52 84 70 O 11 128 173 102 Te Lv sulfur Se Po Yb No oxygen tellurium selenium polonium nobelium ytterbium livermorium – 7 VV P 14 15 31 33 75 51 83 69 N Bi 122 209 169 101 As Sb Md Tm arsenic thulium bismuth nitrogen antimony phosphorus mendelevium m n l 9 4 – – 6 tin 82 12 14 28 32 73 50 68 C IV Si F lead 11 11 Er 207 167 100 Sn Pb Ge silico Fm erbium carbon fermium fleroviu germanium l l 5 n – 5 11 B 27 31 70 49 13 67 99 81 III T A 11 I 204 165 Es Ho boron Ga indium gallium thallium holmium aluminium einsteinium m 2 2 – – 80 48 30 65 98 66 zinc 11 11 201 Cf 163 Zn Dy Cd Hg Cn mercury cadmiu californium dysprosium copernicium – – 79 97 64 47 29 65 111 gold 108 197 159 silver Tb Bk Ag Au Cu Rg copper terbium berkelium roentgenium m l 0 – – 28 64 59 46 78 96 Ni Pt 11 106 195 157 Ds Pd nicke Gd curium Cm platinum palladium gadolinium darmstadtiu .t.p.) ble of Elements Ta m Group r – – 27 63 59 45 77 95 I 103 192 109 152 Mt Eu Co Rh cobalt iridium Am rhodium europium americium meitneriu 1 1 – – 26 62 56 44 76 94 H iron 101 190 108 150 Fe Hs Pu Os Ru Sm osmium hassium hydrogen plutonium samarium ruthenium The Periodic e m – – – – 93 61 25 55 43 75 Tc 186 107 Bh Np Re Mn Pm rhenium bohriu neptunium technetium manganes promethium – 92 60 24 52 42 96 74 U W 144 238 184 106 Cr Sg Nd Mo uranium tungsten chromium neodymium seaborgium s molybdenum at room temperature and pressure (r 3 dm

– V 51 41 93 73 23 59 91 Pr 181 105 141 231 Ta Pa name Nb Db Key niobium tantalum dubnium vanadium protactinium praseodymium atomic number relative atomic mas m atomic symbol – 22 48 40 91 72 90 58 Ti Zr Hf Rf 178 104 140 232 Th Ce cerium thorium titanium hafnium zirconium rutherfordiu – 57 89 Y 21 45 39 89 139 La Ac Sc yttrium 57–71 actinium actinoids 89–103 scandium lanthanum lanthanoids I 9 – 4 24 40 88 12 20 38 88 56 Sr 137 Be Ba Ca Ra Mg barium radium calcium beryllium strontium magnesium II 3 7 – 11 K 19 37 55 87 23 39 85 Li Fr 133 Cs Na Rb lithium sodium caesium francium rubidium potassium actinoids The volume of one mole any gas is 24 lanthanoids

CHEMISTRY 5070/31 Paper 3 Practical Test October/November 2016 1 hour 30 minutes Candidates answer on the Question Paper. Additional Materials: As listed in the Confidential Instructions

READ THESE INSTRUCTIONS FIRST

Answer all questions. Electronic calculators may be used. Qualitative Analysis Notes are printed on page 8. You should show the essential steps in any calculations and record experimental results in the spaces provided on the Question Paper.

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 6 printed pages and 2 blank pages.

DC (ST) 107576/2 © UCLES 2016 [Turn over 2

1 Mangalloy is made by alloying steel with manganese. The percentage by mass of manganese in mangalloy can be determined by converting all the manganese in the alloy into aqueous manganate(VII) ions and then using the solution to titrate aqueous iron(II) sulfate.

No indicator is needed for this titration as the products of the reaction are almost colourless and one drop of aqueous manganate(VII) ions in excess produces a permanent pale pink colour.

– P is an aqueous solution of manganate(VII) ions, MnO4 . The solution was prepared by converting all the manganese in a 2.12 g sample of mangalloy into manganate(VII) ions and making the final volume up to 250 cm3 by adding water.

Q is 0.0800 mol / dm3 iron(II) sulfate.

(a) Put P into the burette.

The colour of P makes it difficult to see the bottom of the meniscus so you should take all your readings using the top of the meniscus.

Pipette a 25.0 cm3 (or 20.0 cm3) portion of Q into a flask.

Add P from the burette. At first the purple colour disappears quickly but as more P is added the colour disappears less quickly. At the end-point, one drop of P produces a pale pink colour that does not disappear on swirling.

Record your results in the table, repeating the titration as many times as you consider necessary to achieve consistent results.

Results

Burette readings

titration number 1 2 final reading / cm3 initial reading / cm3 volume of P used / cm3 best titration results (✓)

Summary

Tick (✓) the best titration results.

Using these results, the average volume of P required was ...... cm3.

Volume of Q used was ...... cm3. [12]

(b) Q is 0.0800 mol / dm3 iron(II) sulfate.

Calculate the number of moles of iron(II) sulfate present in the volume of Q used.

number of moles of iron(II) sulfate ...... [1]

(c) Using your answer from (b), calculate the number of moles of manganate(VII) ions present in the average volume of P required. [Five moles of iron(II) sulfate react with one mole of manganate(VII) ions.]

number of moles of manganate(VII) ions ...... [1]

(d) Using your answer from (c), calculate the number of moles of manganate(VII) ions in 250 cm3 of P.

number of moles of manganate(VII) ions in 250 cm3 of P ...... [1]

(e) Using your answer from (d), calculate the mass of manganese in the 2.12 g sample of mangalloy. [The relative atomic mass of manganese is 55.]

mass of manganese in 2.12 g of mangalloy ...... g [1]

(f) Using your answer from (e), calculate the percentage by mass of manganese in mangalloy.

percentage by mass of manganese in mangalloy ...... % [1]

[Total: 17]

2 You are provided with solution R and solid S. Carry out the following tests and record your observations in the table. You should test and name any gas evolved.

test test observations no. 1 (a) To 1 cm depth of R in a boiling tube, add 2 drops of litmus solution.

(b) To the mixture from (a), add about twice the volume of aqueous sodium hydroxide.

Keep this mixture for use in test 2.

2 To the mixture from test 1, add a piece of aluminium and warm the boiling tube until reaction just begins.

3 (a) To 1 cm depth of R in a boiling tube, add an equal volume of aqueous iron(II) sulfate. Heat the mixture until the liquid just begins to boil.

(b) To the mixture from (a), add aqueous sodium hydroxide until no further change occurs.

4 To 2 cm depth of R in a test-tube, add a piece of magnesium.

test test observations no. 5 To 2 cm depth of R in a test-tube, add a small amount of S.

Keep this solution for use in tests 6 and 7.

6 Transfer about half of the solution from test 5 to a test-tube and add aqueous sodium hydroxide until no further change occurs.

7 To the rest of the solution from test 5 in a test- tube, add aqueous ammonia until no further change occurs.

8 To a small amount of S in a hard-glass test-tube, add an equal amount of ammonium chloride and mix the solids together. Heat the mixture.

[19]

Conclusions

Give the formula of a cation and the formula of an anion in R.

The formula of a cation in R is ......

The formula of an anion in R is ......

Give the formula of a cation and the formula of an anion in S.

The formula of a cation in S is ......

The formula of an anion in S is ...... [4]

[Total: 23]

BLANK PAGE

QUALITATIVE ANALYSIS NOTES

Tests for anions

anion test test result 2– carbonate (CO3 ) add dilute acid effervescence, carbon dioxide produced chloride (Cl –) acidify with dilute nitric acid, then add white ppt. [in solution] aqueous silver nitrate iodide (I–) acidify with dilute nitric acid, then add yellow ppt. [in solution] aqueous silver nitrate – nitrate (NO3 ) add aqueous sodium hydroxide then ammonia produced [in solution] aluminium foil; warm carefully 2– sulfate (SO4 ) acidify with dilute nitric acid, then add white ppt. [in solution] aqueous barium nitrate

Tests for aqueous cations

cation effect of aqueous sodium hydroxide effect of aqueous ammonia white ppt., soluble in excess giving a white ppt., insoluble in excess aluminium (Al 3+) colourless solution + ammonium (NH4 ) ammonia produced on warming – calcium (Ca2+) white ppt., insoluble in excess no ppt., or very slight white ppt. copper(II) (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

Tests for gases

gas test and test result

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

CHEMISTRY 5070/32 Paper 3 Practical Test October/November 2016 1 hour 30 minutes Candidates answer on the Question Paper. Additional Materials: As listed in the Confidential Instructions

READ THESE INSTRUCTIONS FIRST

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 6 printed pages and 2 blank pages.

1 The percentage by mass of iron in steel can be determined by converting all the iron in the steel into aqueous iron(II) ions and titrating portions of the solution with aqueous potassium manganate(VII).

No indicator is needed for this titration as the products of the reaction are almost colourless and one drop of aqueous potassium manganate(VII) in excess produces a permanent pale pink colour.

P is an aqueous solution of iron(II) ions, Fe2+. The solution was prepared by converting all the iron in a 3.12 g sample of steel into iron(II) ions and making the final volume up to 500 cm3 by adding water.

Q is 0.0200 mol/dm3 potassium manganate(VII).

(a) Put Q into the burette.

The colour of Q makes it difficult to see the bottom of the meniscus so you should take all your readings using the top of the meniscus.

Pipette a 25.0 cm3 (or 20.0 cm3) portion of P into a flask.

Add Q from the burette. At first the purple colour disappears quickly but as more Q is added the colour disappears less quickly. At the end-point, one drop of Q produces a pale pink colour that does not disappear on swirling.

Record your results in the table, repeating the titration as many times as you consider necessary to achieve consistent results.

Results

Burette readings

titration number 1 2 final reading / cm3 initial reading / cm3 volume of Q used / cm3 best titration results (✓)

Summary

Tick (✓) the best titration results.

Using these results, the average volume of Q required was ...... cm3.

Volume of P used was ...... cm3. [12]

(b) Q is 0.0200 mol/dm3 potassium manganate(VII).

Calculate the number of moles of potassium manganate(VII) present in the average volume of Q required.

number of moles of potassium manganate(VII) ...... [1]

(c) Using your answer from (b), calculate the number of moles of iron(II) ions present in the volume of P used in each titration. [Five moles of iron(II) ions react with one mole of potassium manganate(VII) ions].

number of moles of iron(II) ions ...... [1]

(d) Using your answer from (c), calculate the number of moles of iron(II) ions in 500 cm3 of P.

number of moles of iron(II) ions in 500 cm3 of P ...... [1]

(e) Using your answer from (d), calculate the mass of iron in the 3.12 g sample of steel. [The relative atomic mass of iron is 56.]

mass of iron in 3.12 g of the steel ...... g [1]

(f) Using your answer from (e), calculate the percentage by mass of iron in the steel.

percentage by mass of iron in the steel ...... % [1]

[Total: 17]

2 You are provided with solution R and solid S. Carry out the following tests and record your observations in the table. You should test and name any gas evolved.

test test observations no. 1 (a) To 1 cm depth of R in a boiling tube, add a drop of methyl orange indicator.

(b) To the mixture from (a), add about twice the volume of aqueous sodium hydroxide.

Keep this mixture for use in test 2.

2 To the mixture from test 1, add a piece of aluminium and warm the boiling tube until reaction just begins.

3 (a) To 1 cm depth of R in a test-tube, add an equal volume of aqueous potassium iodide. Warm the mixture.

(b) Allow the mixture to cool and then add a few drops of aqueous starch.

4 To 2 cm depth of R in a boiling tube, add a small amount of copper(II) oxide and then gently warm the mixture.

test test observations no. 5 To 2 cm depth of R in a test-tube, add a small amount of S.

Keep this solution for use in tests 6 and 7.

6 Transfer about half of the solution from test 5 to a test-tube and add aqueous sodium hydroxide until no further change occurs.

7 To the rest of the solution from test 5 in a test-tube, add aqueous ammonia until no further change occurs.

8 To a small amount of S in a hard-glass test-tube, add an equal amount of ammonium chloride and mix the solids together. Heat the mixture.

[19]

Conclusions

Give the formula of a cation and the formula of an anion in R.

The formula of a cation in R is ......

The formula of an anion in R is ......

Give the formula of a cation and the formula of an anion in S.

The formula of a cation in S is ......

The formula of an anion in S is ...... [4]

[Total: 23]

BLANK PAGE

QUALITATIVE ANALYSIS NOTES Tests for anions

Tests for aqueous cations

Tests for gases

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

CHEMISTRY 5070/41 Paper 4 Alternative to Practical October/November 2016 1 hour Candidates answer on the Question Paper. No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Answer all questions. Write your answers in the spaces provided in the Question Paper. Electronic calculators may be used.

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.

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

1 A student separates a mixture of pentane and hexane using the apparatus shown. Pentane collects in the conical flask.

thermometer

water in

A water out

conical flask

mixture of pentane and hexane

heat

(a) (i) Name apparatus A.

...... [1]

(ii) What is the purpose of apparatus A?

...... [1]

(iii) Name apparatus B.

...... [1]

(b) Identify two errors in the student’s apparatus.

1......

2...... [2]

The errors are corrected before the separation is started.

...... [1]

(d) (i) State why a Bunsen burner should not be used to heat the mixture of pentane and hexane.

...... [1]

(ii) What should be used instead of a Bunsen burner?

...... [1]

(e) Suggest why pentane collects in the conical flask before hexane.

......

...... [2]

[Total: 10]

2 A student investigates the electrolysis of aqueous copper(II) sulfate using the apparatus shown.

+ –

anode cathode

aqueous copper(II) sulfate

A solid is produced at the cathode. A gas is produced at the anode.

(a) From what material is the anode made?

...... [1]

(b) Describe the appearance of the solid produced at the cathode.

...... [1]

name of gas ......

test and observation ...... [2]

[Total: 4]

In questions 3 to 5 inclusive, place a tick (✓) in the box against the correct answer.

3 A student finds that a compound contains 4.8 g of carbon, 0.8 g of hydrogen and 6.4 g of oxygen.

[Ar: C, 12; H, 1; O, 16]

What is the empirical formula of the compound?

(a) CH2O

(b) C2H2O

(d) C4H8O4

[Total: 1]

4 Aqueous solutions of which of the following pairs of compounds will not react together to form a precipitate?

(a) silver nitrate and ammonium iodide

(b) silver nitrate and barium chloride

(d) sodium hydroxide and ammonium chloride

[Total: 1]

5 A student adds the catalyst manganese(IV) oxide to aqueous hydrogen peroxide. The hydrogen peroxide decomposes.

2H2O2(aq) 2H2O(l) + O2(g)

The student measures the volume of oxygen given off at regular time intervals. This is experiment 1.

The student repeats the experiment using one different condition. This is experiment 2.

Graphs for both experiments 1 and 2 are shown.

volume of experiment 1 oxygen experiment 2

0 0 time

What is the different condition used in experiment 2?

(a) A greater mass of the manganese(IV) oxide was added.

(b) A lower temperature was used.

(d) A higher concentration of aqueous hydrogen peroxide was used.

[Total: 1]

6 Copper(II) oxide and carbon are both black solids. Copper(II) oxide reacts with dilute sulfuric acid forming aqueous copper(II) sulfate. Carbon does not react with dilute sulfuric acid.

Describe how you would obtain a pure, dry sample of carbon from a mixture of powdered copper(II) oxide and powdered carbon.

You are provided with

• all the apparatus normally found in a laboratory, • the mixture of powdered copper(II) oxide and powdered carbon, • dilute sulfuric acid, • distilled water.

No other chemicals are available.

You should give experimental details and the observations occurring at each stage of the procedure.

......

[Total: 5]

7 Limestone is impure calcium carbonate. A student does an experiment to determine the percentage by mass of calcium carbonate in a sample of limestone. The sample of limestone is placed in a previously weighed container and reweighed.

mass of container + limestone = 10.22 g

mass of empty container = 5.72 g

(a) Calculate the mass of limestone used in the experiment.

...... g [1]

The student transfers the sample of limestone into a beaker and adds 50.0 cm3 of 2.00 mol / dm3 hydrochloric acid, an excess. The calcium carbonate reacts with the hydrochloric acid.

l l CaCO3 + 2HC CaC 2 + CO2 + H2O

The student transfers the contents of the beaker into another container and the volume is made up to 250 cm3 with distilled water. This is solution T.

(b) Name the container in which solution T should be made.

...... [1]

25.0 cm3 of T is transferred to a conical flask and a few drops of methyl orange indicator are added.

An aqueous solution of 0.100 mol / dm3 sodium hydroxide is put into a burette and run into the conical flask until the end-point is reached.

The colour changes from ...... to ...... [1]

(d) Three titrations are done. The diagrams show parts of the burette with the liquid levels at the beginning and end of each titration.

titration 1 titration 2 titration 3

0 29 16 45 4 32

1 30 17 46 5 33

2 31 18 47 6 34

Use the diagrams to complete the results table.

titration number 1 2 3 final burette reading / cm3 initial burette reading / cm3 volume of 0.100 mol / dm3 sodium hydroxide / cm3 best titration results (✓)

Summary

Tick (✓) the best titration results.

Using these results, the average volume of 0.100 mol / dm3 sodium hydroxide is

...... cm3. [4]

(e) Calculate the number of moles of sodium hydroxide in the average volume of 0.100 mol / dm3 sodium hydroxide in (d).

...... moles [1]

(f) Using the equation

l l NaOH + HC NaC + H2O

and your answer to (e), deduce the number of moles of hydrochloric acid in 25.0 cm3 of T.

...... moles [1]

(g) Calculate the number of moles of hydrochloric acid in 250 cm3 of T.

...... moles [1]

(h) Calculate the number of moles of hydrochloric acid in the original 50.0 cm3 of 2.00 mol / dm3 hydrochloric acid.

...... moles [1]

(i) Using your answers to (h) and (g), calculate the number of moles of hydrochloric acid that reacted with the calcium carbonate in the sample of limestone.

...... moles [1]

(j) Using the equation

l l CaCO3 + 2HC CaC 2 + CO2 + H2O

and your answer to (i), calculate the number of moles of calcium carbonate that reacted with the hydrochloric acid.

...... moles [1]

(k) Calculate the relative formula mass of calcium carbonate.

[Ar: Ca, 40; C, 12; O, 16]

...... [1]

(l) Using your answers to (j) and (k), calculate the mass of calcium carbonate in the sample of limestone.

...... g [1]

(m) Using your answers to (a) and (l), calculate the percentage by mass of calcium carbonate in the sample of limestone.

...... % [1]

[Total: 16]

8 The table shows the tests a student does on compound L.

L contains three different ions.

Complete the table by adding the conclusion for (a), the observations for (b) (i), (ii) and (iii), the conclusions for (c)(i) and (ii) and both the test and observation which lead to the conclusion for test (d). Any gases produced should be identified by test, result and name.

test observations conclusion (a) L is dissolved in water A coloured solution is and the solution divided formed. into three parts for tests (b), (c) and (d). [1] (b) (i) To the first part, L contains Fe2+ ions. aqueous sodium hydroxide is added until a change is seen.

(ii) An excess of L contains Fe2+ ions. aqueous sodium hydroxide is added to the mixture from (i).

+ (iii) This mixture is then L contains NH4 ions. heated.

[4] (c) (i) To the second part, A green precipitate forms. aqueous ammonia is added until a change is seen.

(ii) An excess of The precipitate is insoluble aqueous ammonia in excess. is added to the mixture from (i). [1] 2− (d) L contains SO4 ions.

[3]

(e) The green precipitate that forms in test (c) turns brown at the surface after a few minutes. Suggest why.

......

...... [2]

9 When magnesium powder is added to an excess of hydrochloric acid, the temperature rises.

(a) (i) What type of reaction does the temperature rise indicate?

...... [1]

(ii) In addition to the temperature rise, give two observations that can be made as the reaction takes place.

......

...... [2]

(iii) Construct an equation for the reaction between magnesium powder and hydrochloric acid.

...... [1]

(b) A student does an experiment to determine the amount of heat produced in the reaction. The student transfers 50.0 cm3 of 2.0 mol / dm3 hydrochloric acid to a beaker. The temperature of the solution is 20.0 °C. When 0.20 g of magnesium powder is added to the hydrochloric acid the temperature rises rapidly.

magnesium thermometer powder

50.0 cm3 2.0 mol / dm3

hydrochloric acid

The student records the temperature of the mixture at one minute intervals.

time / min temperature of the mixture / °C 1.0 37.4 2.0 35.2 3.0 33.1 4.0 31.1 5.0 29.0 6.0 26.9

Plot the results on the grid. Draw a straight line through the points. Extend the line until it intersects the y-axis.

35 temperature of the mixture / °C 30

20 0 1 2 3 4 5 6 time / min [3]

(c) (i) Use your graph to determine the temperature at 0 minutes. This gives the maximum temperature of the mixture reached in the reaction.

...... °C [1]

(ii) The initial temperature of the hydrochloric acid was 20.0 °C. Use your answer to (c)(i) to calculate the maximum temperature rise.

...... °C [1]

(d) 4.2 joules (J) of heat energy are required to raise the temperature of 1.0 cm3 of hydrochloric acid by 1 °C.

(i) Calculate the amount of heat energy in joules (J) required to raise the temperature of 50.0 cm3 of hydrochloric acid by 1 °C.

...... J [1]

(ii) Calculate the amount of heat energy in joules (J) required to raise the temperature of 50.0 cm3 of hydrochloric acid by the maximum temperature rise calculated in (c)(ii).

...... J [1]

[Total: 11]

BLANK PAGE

CHEMISTRY 5070/42 Paper 4 Alternative to Practical October/November 2016 1 hour Candidates answer on the Question Paper. No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Answer all questions. Write your answers in the spaces provided in the Question Paper. Electronic calculators may be used.

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.

This document consists of 16 printed pages.

1 A student uses acidified aqueous potassium manganate(VII) to oxidise ethanol to ethanoic acid.

bung

water in

A water out

ethanol and acidified aqueous potassium manganate(VII)

heat

(a) (i) Name apparatus A.

...... [1]

(ii) What is the purpose of apparatus A?

...... [1]

(b) Identify two errors in the student’s apparatus.

1......

2...... [2]

The errors are corrected before the student begins heating.

...... [1]

(ii) What should be used instead of a Bunsen burner?

...... [1]

(d) Name the process that the student uses to separate ethanoic acid from the mixture after heating.

...... [1]

(e) The ethanoic acid is heated with another sample of ethanol and a catalyst of sulfuric acid.

Name the organic product.

...... [1]

[Total: 8]

2 The apparatus shown is used to electrolyse dilute sulfuric acid.

carbon anode carbon cathode

dilute sulfuric acid

+ –

(a) Name the gas that collects at the anode. Give a test and observation to identify this gas.

name of gas ......

test and observation ...... [2]

(b) Name the gas that collects at the cathode. Give a test and observation to identify this gas.

name of gas ......

test and observation ...... [2]

shown.

+ –

carbon anode carbon cathode

electrolyte

Complete the table.

electrolyte name of product observations at name of product observations at at the anode the anode at the cathode the cathode

concentrated black solid bubbles of aqueous sodium / brown solution colourless gas iodide concentrated aqueous bubbles of pink solid copper(II) colourless gas sulfate concentrated aqueous sodium chlorine hydrogen chloride [6]

[Total: 10]

In questions 3 to 6 inclusive, place a tick (✓) in the box against the correct answer.

3 A student burns 4.8 g of an element X in excess oxygen. The mass of the oxide produced is 8.0 g.

What is the empirical formula of the oxide of X?

[Ar: X, 24; O, 16]

(a) XO

(b) X2O

(d) X3O5

[Total: 1]

4 The chromatogram shows the results of chromatography using mixture Z as well as individual dyes labelled 1, 2, 3 and 4.

starting line solvent flow Z 1 2 3 4

Which of the dyes does Z contain?

(a) 1 only

(b) 2 and 3

(d) 4 only

[Total: 1]

5 A student adds excess zinc to hydrochloric acid and measures the volume of hydrogen gas given off at regular time intervals. This is experiment 1.

The student makes a change to one of the conditions and then repeats the experiment. This is experiment 2.

The volume of hydrochloric acid is the same in both experiments.

Graphs for both experiments 1 and 2 are shown.

experiment 2

volume experiment 1 of hydrogen

0 0 time

What is the different condition used in experiment 2?

(a) A catalyst is added.

(b) A higher temperature is used.

(d) A higher concentration of hydrochloric acid is used.

[Total: 1]

6 A student passes air backwards and forwards over heated copper using the apparatus shown. The original volume of air in the apparatus is 50.0 cm3.

copper

gas syringe heat gas syringe

The experiment continues until the volume of gas stops changing. Some unreacted copper remains.

What is the final volume of gas in the apparatus?

[All volumes are measured at room temperature and pressure.]

(a) 10 cm3

(b) 30 cm3

(d) 60 cm3

[Total: 1]

7 Vinegar contains dilute ethanoic acid. Different brands of vinegar contain different concentrations of ethanoic acid.

You are provided with two different brands of colourless vinegar as well as the apparatus and chemicals normally found in a laboratory.

Describe how you would carry out experiments to find out which of the two brands contains the higher concentration of ethanoic acid.

You should give experimental details and the observations occurring at each stage of the procedure.

......

[Total: 5]

8 A student does an experiment to determine the percentage by mass of copper in a sample of impure copper. The sample of impure copper is placed in a previously weighed container and reweighed.

mass of container + impure copper = 7.45 g

mass of empty container = 5.72 g

(a) Calculate the mass of impure copper used in the experiment.

...... g [1]

The student transfers the sample of impure copper to a beaker, adds excess concentrated nitric acid and stirs until all the solid has dissolved. The copper reacts with the nitric acid producing aqueous copper nitrate as shown in equation 1.

equation 1 Cu + 4HNO3 Cu(NO3)2 + 2NO2 + 2H2O

An excess of aqueous potassium iodide and an excess of dilute hydrochloric acid are then added to the beaker. A further reaction occurs as shown in equation 2.

I l l I I equation 2 2Cu(NO3)2 + 4K + 4HC 4KC + 2Cu + 4HNO3 + 2

The contents of the beaker are transferred to a suitable container and made up to 250 cm3 with distilled water. This is solution J.

(b) Name the container in which solution J should be made.

...... [1]

The student transfers 25.0 cm3 of J to a conical flask and adds a few drops of a suitable indicator.

3 An aqueous solution of 0.100 mol / dm sodium thiosulfate, Na2S2O3, is put into a burette and run into the conical flask until the end-point is reached. The reaction between sodium thiosulfate, I Na2S2O3, and iodine, 2, is shown in equation 3. I I equation 3 2Na2S2O3 + 2 2Na + Na2S4O6

(c) Three titrations are done. The diagrams show parts of the burette with the liquid levels at the beginning and end of each titration.

titration 1 titration 2 titration 3

0 20 24 47 10 32

1 21 25 48 11 33

2 22 26 49 12 34

Use the diagrams to complete the results table.

titration number 1 2 3 final burette reading / cm3 initial burette reading / cm3 volume of 0.100 mol / dm3 3 Na2S2O3 / cm best titration results (✓)

Summary

Tick (✓) the best titration results.

3 Using these results, the average volume of 0.100 mol / dm Na2S2O3 is

...... cm3. [4]

3 (d) Calculate the number of moles of Na2S2O3 in the average volume of 0.100 mol / dm Na2S2O3.

...... moles [1]

I 3 (e) Use your answer to (d) and equation 3 to calculate the number of moles of 2 in 25.0 cm of J.

I I equation 3 2Na2S2O3 + 2 2Na + Na2S4O6

...... moles [1]

I 3 (f) Use your answer to (e) to calculate the number of moles of 2 in 250 cm of J.

...... moles [1]

(g) Use your answer to (f) and equation 2 to calculate the number of moles of Cu(NO3)2 that I produce the number of moles of 2 calculated in (f). I l l I I equation 2 2Cu(NO3)2 + 4K + 4HC 4KC + 2Cu + 4HNO3 + 2

...... moles [1]

(h) Use your answer to (g) and equation 1 to deduce the number of moles of Cu that produce the number of moles of Cu(NO3)2 calculated in (g).

equation 1 Cu + 4HNO3 Cu(NO3)2 + 2NO2 + 2H2O

...... moles [1]

(i) Use your answer to (h) to calculate the mass of copper in the sample of impure copper.

[Ar: Cu, 63.5]

...... g [1]

(j) Use your answers to (i) and (a) to calculate the percentage by mass of copper in the sample of impure copper.

...... % [1]

[Total: 13]

9 The following table shows the tests a student does on a mixture L, which contains two compounds.

L contains three different ions.

Complete the table by adding the conclusion for (a), the observations for (b) (i), (ii) and (iii), the conclusions for tests (c) (i) and (ii), and both the test and observation which lead to the conclusion for test (d). Any gases produced should be identified by test, result and name.

test observation conclusion (a) L is dissolved in water A colourless solution is and the solution divided formed. into three parts for tests (b), (c) and (d). [1] (b) (i) To the first part, L contains Al 3+, Zn2+ or aqueous sodium Ca2+ ions. hydroxide is added until a change is seen.

(ii) An excess of L contains Al 3+ or Zn2+ ions. aqueous sodium hydroxide is added to the mixture from (i).

+ (iii) This mixture is then L contains NH4 ions. heated.

[4] (c) (i) To the second part, A white precipitate forms. aqueous ammonia is added until a change is seen.

(ii) An excess of The precipitate is insoluble aqueous ammonia in excess. is added to the mixture from (i). [1] 2− (d) L contains SO4 ions.

[3]

(e) Give the formulae of the two compounds which are present in mixture L.

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

[Total: 11]

10 When metal M is added to aqueous copper(II) sulfate the temperature rises.

(a) What type of reaction does the temperature rise indicate?

...... [1]

The equation for the reaction is shown.

M + CuSO4 MSO4 + Cu

A student transfers 25.0 cm3 of 2.7 mol / dm3 of aqueous copper(II) sulfate to a glass beaker. A 0.4 g sample of metal M is added to the beaker and the mixture is stirred. The student records the maximum temperature rise with a thermometer.

M thermometer

25.0 cm3 2.7 mol / dm3

copper(II) sulfate

The student repeats the experiment using different masses of metal M and in each case calculates and records the maximum temperature rise.

mass of M / g maximum temperature rise / °C 0.4 2.2 0.8 4.4 1.2 6.6 1.6 8.8 2.0 8.8 2.4 8.8

(b) Plot the maximum temperature rise against the mass of M on the grid and draw two intersecting straight lines through the points.

maximum temperature rise / °C 4

0 0.0 0.4 0.8 1.2 1.6 2.0 2.4 mass of M / g [3]

...... g [1]

(ii) Use your graph to determine the maximum temperature rise which would occur if 1.5 g of M is used in the experiment.

...... °C [1]

(d) (i) Calculate the number of moles of copper(II) sulfate in 25.0 cm3 of 2.7 mol / dm3 aqueous copper(II) sulfate.

...... moles [1]

(ii) Use your graph to deduce the mass of M that reacts completely with 25.0 cm3 of 2.7 mol / dm3 aqueous copper(II) sulfate.

...... g [1]

(iii) Use the equation

M + CuSO4 MSO4 + Cu

and your answers to (d)(i) and (d)(ii) to calculate the relative atomic mass of metal M.

...... [1]

[Total: 9]