Cambridge IGCSE Chemistry (BES) 0439 — 2017 Oct/Nov Paper 3 · Variant 1

READ THESE INSTRUCTIONS FIRST Write your Center 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. Answer all questions. Electronic calculators may be used. A copy of the Periodic Table is printed on page 16. You may lose marks if you do not show your working or if you do not use appropriate units. 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. CHEMISTRY (US) 0439/31 Paper 3 Theory (Core) October/November 2017  1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. Cambridge International Examinations Cambridge International General Certificate of Secondary Education This document consists of 15 printed pages and 1 blank page. [Turn over IB17 11_0439_31/RP © UCLES 2017 *5882978846*

2 0439/31/O/N/17 © UCLES 2017 1 The diagram shows the structures of five substances, A, B, C, D and E. A B D E C Br Br C H C H H H C H C Br Br H H H Na+ Br – Na+ Br – Na+ Br – Na+ Br – Br – Na+ Na+ Br – F F F Br Answer the following questions using only the structures in the diagram. Each structure may be used once, more than once or not at all. (a) Which structure, A, B, C, D or E, (i) is a diatomic molecule, … [1] (ii) contains ions, … [1] (iii) decolorizes aqueous bromine, … [1] (iv) conducts electricity when molten, … [1] (v) contains atoms of two different halogens? … [1] (b) Bromine is an element. What is meant by the term element ? … … [1] (c) Bromine melts at –7 °C and boils at 59 °C. What is the physical state of bromine at –15 °C? Explain your answer. … … [2] [Total: 8]

3 0439/31/O/N/17 © UCLES 2017 [Turn over 2 The table shows the composition of the atmosphere of the planet Neptune. gas present percentage of gas in Neptune’s atmosphere helium 19.5 hydrogen 78.8 methane other gases 0.2 (a) Complete the table to calculate the percentage of methane in Neptune’s atmosphere. [1] (b) Describe how Neptune’s atmosphere differs from the Earth’s atmosphere. Give three differences. 1 … … 2 … … 3 … … [3] (c) Methane is a covalent compound. Complete the diagram to show ● the arrangement of electrons in a molecule of methane, ● the symbols of the atoms present. Show outer shell electrons only. [2]

4 0439/31/O/N/17 © UCLES 2017 (d) Isotopes of hydrogen are present in Neptune’s atmosphere. (i) What is meant by the term isotopes? … … [1] (ii) An atom of hydrogen has three nucleons. Deduce the number of protons and neutrons present in one atom of this isotope of hydrogen. Use your Periodic Table to help you. number of protons … number of neutrons … [2] (e) Other gases present in Neptune’s atmosphere include ethane and water vapor. (i) Calculate the relative molecular mass of ethane, C2H6. Use your Periodic Table to help you. relative molecular mass = … [2] (ii) Describe a chemical test for water. test … result … [2] [Total: 13]

5 0439/31/O/N/17 © UCLES 2017 [Turn over 3 The following substances are present in a liquid floor cleaner. colored dyes ethanol preservatives sodium carbonate (a) (i) Balance the chemical equation for the complete combustion of ethanol. C2H5OH + 3O2 …CO2 + …H2O [2] (ii) Draw the structure of an ethanol molecule showing all of the atoms and all of the bonds. [2] (b) Aqueous sodium carbonate is alkaline. (i) Which one of the following pH values is alkaline? Put a circle around the correct answer. pH 3 pH 6 pH 7 pH 10 [1] (ii) Aqueous sodium carbonate is colorless. An excess of aqueous sodium carbonate is added to a solution of dilute sulfuric acid and methyl orange. Describe the color change. from … to … [2] (iii) The chemical equation for the reaction between sodium carbonate and dilute sulfuric acid is shown. Na2CO3 + H2SO4 Na2SO4 + CO2 + H2O Write the word equation for this reaction. … [2]

6 0439/31/O/N/17 © UCLES 2017 (c) Preservatives stop the growth of bacteria and fungi. State the name of an acidic gas used to preserve food. … [1] (d) The colored dyes in the liquid floor cleaner can be separated using the apparatus shown. P … Q … (i) Complete the boxes to label P and Q. [2] (ii) State the name of this method of separation. … [1] (iii) On the diagram, put an X to show where the mixture of colored dyes is placed at the start of the experiment. [1] [Total: 14]

7 0439/31/O/N/17 © UCLES 2017 [Turn over 4 The table shows the properties of four substances. substance boiling point electrical conductivity of solid electrical conductivity when molten density in g / cm3 graphite 2.25 iodine low does not conduct does not conduct 4.93 potassium high conducts 0.86 zinc chloride high does not conduct conducts 2.91 (a) Complete the table to show the electrical conductivity of solid graphite and solid potassium. [2] (b) Give one piece of evidence from the table that shows that iodine is a simple covalent substance. … [1] (c) What information in the table shows that zinc chloride is an ionic compound? … … [2] (d) Molten zinc chloride can be electrolyzed. Predict the products of this electrolysis at the positive electrode (anode), … the negative electrode (cathode). … [2] (e) Aqueous iodine is formed when aqueous chlorine is added to aqueous potassium iodide. Use ideas about reactivity to explain why this reaction occurs. … … [1] [Total: 8]

8 0439/31/O/N/17 © UCLES 2017 5 Titanium is extracted from an ore which contains titanium(IV) oxide, TiO2. (a) (i) Balance the chemical equation for the first step in this extraction. TiO2 + …C + …Cl 2 TiCl 4 + 2CO [2] (ii) Explain why the conversion of carbon to carbon monoxide is an oxidation reaction. … [1] (b) Titanium is a transition element. Sodium is a Group I element. Describe two differences in the physical properties of titanium and sodium. 1 … … 2 … … [2] (c) The properties and relative reactivity with water of some Group I elements are shown in the table. element density in g / cm3 melting point in °C relative reactivity with water lithium 0.53 181 sodium 98 forms bubbles rapidly but does not burst into flames potassium 0.86 forms bubbles very rapidly and bursts into flames rubidium 1.53 39 reacts explosively (i) Complete the table ● for the relative reactivity of lithium with water, ● to predict the melting point of potassium.  [2] (ii) Describe the general trend in the density of the Group I elements. … [1] (d) Is lithium oxide an acidic oxide or a basic oxide? Explain your answer. … … [1] [Total: 9]

9 0439/31/O/N/17 © UCLES 2017 [Turn over 6 The diagram shows a fractionating column used for the fractional distillation of petroleum. kerosene fraction naphtha fraction gasoline fraction refinery gas diesel oil fraction fuel oil fraction lubricating fraction and bitumen (a) Describe the fractional distillation of petroleum. In your answer, include ● where the petroleum enters the fractionating column, ● the relative temperatures in the fractionating column (higher or lower), ● the relative boiling points of the fractions (higher or lower), ● the changes in physical state which occur. … … … … … … … [4]

10 0439/31/O/N/17 © UCLES 2017 (b) Alkenes can be made by cracking the kerosene fraction. (i) What is meant by the term cracking? … … [2] (ii) When butane is cracked, ethene and gas X are produced. C4H10 2C2H4 + X State the name of gas X. … [1] (c) Complete the sentence about the bonding in butane. All the bonds in butane are single … chemical bonds. [1] (d) Ethene is used to make poly(ethene). Which one of the following words describes poly(ethene)? Put a circle around the correct answer. gas monomer polymer solvent [1] [Total: 9]

11 0439/31/O/N/17 © UCLES 2017 [Turn over 7 Bromine is a red-brown liquid which is soluble in cyclohexane. (a) A few drops of liquid bromine were placed at the bottom of a beaker containing cyclohexane. After 3 days, a red-brown color had spread throughout the beaker. at the start after 6 hours after 3 days cyclohexane bromine Explain these observations using the kinetic particle model. … … … … … [3] (b) The structure of a compound containing bromine is shown. H C H Br Br C H C C O O H H H (i) Deduce the molecular formula of this compound showing the number of carbon, hydrogen, oxygen and bromine atoms. … [1] (ii) State the name of the C O O H functional group. … [1]

12 0439/31/O/N/17 © UCLES 2017 (c) The relative atomic mass of bromine is 80. Complete the definition of relative atomic mass using terms from the list. 6 12 an atom an element a molecule average carbon hydrogen total Relative atomic mass is the … mass of naturally occurring atoms of … on a scale where … of the 12C isotope has a mass of exactly … units. [4] (d) Dilute hydrobromic acid reacts with magnesium ribbon. (i) Suggest three ways of increasing the rate of this reaction. 1 … 2 … 3 … [3] (ii) Hydrobromic acid reacts with oxygen. The products are water and bromine. Balance the chemical equation for this reaction. …HBr + O2 2H2O + 2Br2 [1] [Total: 13]

13 0439/31/O/N/17 © UCLES 2017 [Turn over 8 Ammonia is manufactured by combining nitrogen and hydrogen at high temperature and pressure. catalyst nitrogen + hydrogen ammonia (a) (i) What is the meaning of the symbol ? … [1] (ii) What is the purpose of the catalyst? … [1] (b) The graph shows the percentage yield of ammonia at different temperatures. 100 80 60 40 20 0 100 0 200 300 temperature / °C percentage yield of ammonia 400 500 600 (i) Describe how the percentage yield of ammonia changes with temperature. … [1] (ii) Deduce the percentage yield of ammonia at 400 °C. … [1]

14 0439/31/O/N/17 © UCLES 2017 (c) Copper(II) oxide reacts with ammonia. copper(II) oxide + ammonia copper + nitrogen + water When 20 g of copper(II) oxide react with an excess of ammonia, 16 g of copper are formed. Calculate the mass of copper formed when 140 g of copper(II) oxide react with an excess of ammonia. … g [1] (d) Ammonia is used in the manufacture of nylon. Give one use of nylon. … [1] [Total: 6]

15 0439/31/O/N/17 © UCLES 2017 BLANK PAGE 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. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. 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.

16 0439/31/O/N/17 © UCLES 2017 Group The Periodic Table of Elements 1 H hydrogen 1 2 He helium 4 I II III IV V VI VII VIII 3 Li lithium 7 4 Be beryllium 9 atomic number atomic symbol Key name relative atomic mass 11 Na sodium 23 12 Mg magnesium 24 19 K potassium 39 20 Ca calcium 40 37 Rb rubidium 85 38 Sr strontium 88 55 Cs cesium 133 56 Ba barium 137 87 Fr francium – 88 Ra radium – 5 B boron 11 13 Al aluminum 27 31 Ga gallium 70 49 In indium 115 81 Tl thallium 204 6 C carbon 12 14 Si silicon 28 32 Ge germanium 73 50 Sn tin 119 82 Pb lead 207 22 Ti titanium 48 40 Zr zirconium 91 72 Hf hafnium 178 104 Rf rutherfordium – 23 V vanadium 51 41 Nb niobium 93 73 Ta tantalum 181 105 Db dubnium – 24 Cr chromium 52 42 Mo molybdenum 96 74 W tungsten 184 106 Sg seaborgium – 25 Mn manganese 55 43 Tc technetium – 75 Re rhenium 186 107 Bh bohrium – 26 Fe iron 56 44 Ru ruthenium 101 76 Os osmium 190 108 Hs hassium – 27 Co cobalt 59 45 Rh rhodium 103 77 Ir iridium 192 109 Mt meitnerium – 28 Ni nickel 59 46 Pd palladium 106 78 Pt platinum 195 110 Ds darmstadtium – 29 Cu copper 64 47 Ag silver 108 79 Au gold 197 111 Rg roentgenium – 30 Zn zinc 65 48 Cd cadmium 112 80 Hg mercury 201 112 Cn copernicium – 114 Fl flerovium – 116 Lv livermorium – 7 N nitrogen 14 15 P phosphorus 31 33 As arsenic 75 51 Sb antimony 122 83 Bi bismuth 209 8 O oxygen 16 16 S sulfur 32 34 Se selenium 79 52 Te tellurium 128 84 Po polonium – 9 F fluorine 19 17 Cl chlorine 35.5 35 Br bromine 80 53 I iodine 127 85 At astatine – 10 Ne neon 20 18 Ar argon 40 36 Kr krypton 84 54 Xe xenon 131 86 Rn radon – 21 Sc scandium 45 39 Y yttrium 89 57–71 lanthanoids 89–103 actinoids 57 La lanthanum 139 89 Ac lanthanoids actinoids The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.) actinium – 58 Ce cerium 140 90 Th thorium 232 59 Pr praseodymium 141 91 Pa protactinium 231 60 Nd neodymium 144 92 U uranium 238 61 Pm promethium – 93 Np neptunium – 62 Sm samarium 150 94 Pu plutonium – 63 Eu europium 152 95 Am americium – 64 Gd gadolinium 157 96 Cm curium – 65 Tb terbium 159 97 Bk berkelium – 66 Dy dysprosium 163 98 Cf californium – 67 Ho holmium 165 99 Es einsteinium – 68 Er erbium 167 100 Fm fermium – 69 Tm thulium 169 101 Md mendelevium – 70 Yb ytterbium 173 102 No nobelium – 71 Lu lutetium 175 103 Lr lawrencium –

® IGCSE is a registered trademark. This document consists of 7 printed pages. © UCLES 2017 [Turn over Cambridge Assessment International Education Cambridge International General Certificate of Secondary Education CHEMISTRY (US) 0439/31 Paper 3 Core Theory October/November 2017 MARK SCHEME Maximum Mark: 80 Published 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 should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge International will not enter into discussions about these mark schemes. Cambridge International is publishing the mark schemes for the October/November 2017 series for most Cambridge IGCSE®, Cambridge International A and AS Level components and some Cambridge O Level components.

0439/31 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2017 © UCLES 2017 Page 2 of 7 Question Answer Marks 1(a)(i) A 1 1(a)(ii) B 1 1(a)(iii) D 1 1(a)(iv) B 1 1(a)(v) C 1 1(b) substance containing only one type of atom / substance containing atoms (each) with the same number of protons / substance which cannot be broken down further by chemical means 1 1(c) solid 1 –15 °C is below the melting point 1 Question Answer Marks 2(a) 1.5 (%) 1 2(b) any 3 from: • greater percentage of helium (on Neptune) / more helium on Neptune / less helium on Earth • greater percentage of hydrogen (on Neptune) / more hydrogen on Neptune / no hydrogen on Earth / (very) little hydrogen on Earth • no oxygen on Neptune / little oxygen on Neptune (but Earth has 21% oxygen) • greater percentage of methane (on Neptune) / more methane on Neptune / less methane on Earth / more methane on Neptune • more argon on Earth / less argon on Neptune • no nitrogen on Neptune / little nitrogen on Neptune 3 2(c) labels ‘C’ and ‘H’ in the correct circles and no non-bonding electrons or extra bonding electrons 1 one pair of electrons in each overlap area 1

0439/31 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2017 © UCLES 2017 Page 3 of 7 Question Answer Marks 2(d)(i) atoms of the same element with the same number of protons but a different number of neutrons 1 2(d)(ii) number of protons: 1 1 number of neutrons: 2 1 2(e)(i) 30 IF full credit is not awarded, allow 1 mark for (C =) 12 and (H =) 1 2 2(e)(ii) anhydrous / white copper(II) sulfate OR anhydrous / blue cobalt(II) chloride 1 (anhydrous copper(II) sulfate) turns blue OR (anhydrous cobalt(II) chloride) turns pink 1 Question Answer Marks 3(a)(i) 2 (CO2) 1 3 (H2O) 1 3(a)(ii) correct structure showing all of the atoms and all of the bonds including O–H IF full credit is not awarded, allow 1 mark for structure with OH 2 3(b)(i) pH 10 1 3(b)(ii) red / pink 1 to yellow 1 3(b)(iii) sodium carbonate + sulfuric acid → sodium sulfate + carbon dioxide + water IF full credit is not awarded, allow 1 mark for either sodium sulfate OR carbon dioxide + water 2

0439/31 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2017 © UCLES 2017 Page 4 of 7 Question Answer Marks 3(c) sulfur dioxide 1 3(d)(i) P: chromatography paper / filter paper 1 Q: solvent 1 3(d)(ii) chromatography 1 3(d)(iii) X drawn on the baseline 1 Question Answer Marks 4(a) graphite: conducts 1 potassium: conducts 1 4(b) low boiling point 1 4(c) does not conduct when solid but conducts when molten IF full credit is not awarded, allow 1 mark for conducts when molten 2 4(d) positive electrode (anode): chlorine / Cl2 1 negative electrode (cathode): zinc / Zn 1 4(e) chlorine is more reactive than iodine 1 Question Answer Marks 5(a)(i) 2 (C) 1 2 (Cl2) 1 5(a)(ii) carbon gains oxygen / oxidation number of carbon increases / carbon loses electrons 1

0439/31 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2017 © UCLES 2017 Page 5 of 7 Question Answer Marks 5(b) any 2 from: • titanium has a high melting / boiling point ORA • titanium has a high density ORA • titanium is hard / strong ORA 2 5(c)(i) relative reactivity with water: forms bubbles slowly / slower than sodium 1 melting point of potassium: any value between 45–90 (°C) inclusive 1 5(c)(ii) increases down the group / decreases up the group 1 5(d) basic because it is a metal (oxide) 1 Question Answer Marks 6(a) any 4 from: • petroleum vaporised / heated • petroleum enters the fractionating column at the bottom • vapours move up the fractionating column • column is hotter at the bottom / cooler at the top • idea of vapours condensing in different parts of the fractionating column • idea of different fractions having different boiling ranges • fractions (condensing) higher up have lower boiling points ORA 4 6(b)(i) breaking down / decomposing / splitting hydrocarbons 1 into smaller hydrocarbons / into alkanes and alkenes / by heating / using a high temperature 1 6(b)(ii) hydrogen 1 6(c) covalent 1 6(d) polymer 1

0439/31 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2017 © UCLES 2017 Page 6 of 7 Question Answer Marks 7(a) any 3 from: • diffusion • molecules move (from place to place) • (molecules move) randomly • molecules collide • molecules spread out / mix up • (bulk) movement of molecules from areas of where they are at higher concentration to where they are at lower concentration 3 7(b)(i) C4H6O2Br2 1 7(b)(ii) carboxylic acid 1 7(c) average 1 an element 1 an atom 1 12 1 7(d)(i) increasing the concentration of the acid 1 increasing the temperature 1 using magnesium powder / using smaller pieces of magnesium 1 7(d)(ii) 4 (HBr) 1 Question Answer Marks 8(a)(i) reversible reaction 1 8(a)(ii) speed up the reaction / increase the rate of reaction / speed of reaction faster 1

0439/31 Cambridge IGCSE – Mark Scheme PUBLISHED October/November 2017 © UCLES 2017 Page 7 of 7 Question Answer Marks 8(b)(i) decreases as the temperature increases ORA 1 8(b)(ii) 28% 1 8(c) 112 (g) 1 8(d) clothing / named clothing / fishing lines 1