Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2009 Oct/Nov Paper 3 · Variant 1

This document consists of 22 printed pages and 2 blank pages. IB09 11_0654_03/3RP © UCLES 2009 [Turn over *4665247311* For Examiner's Use 1 2 3 4 5 6 7 8 9 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/03 Paper 3 (Extended) October/November 2009 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. A copy of the Periodic Table is printed on page 24. 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. www.XtremePapers.com

3 © UCLES 2009 0654/03/O/N/09 [Turn over For Examiner's Use 1 (a) The Law of Reflection states that when a ray of light is reflected at a surface, the angle of incidence equals the angle of reflection. Complete the diagram to show how a ray of light is reflected by a plane (flat) mirror. Label the angle of incidence and angle of reflection. ray of light mirror [3] (b) When white light passes through a prism, it is split into its component colours. (i) Which colour is refracted most by the prism? [1] (ii) Why are some colours refracted more than others? [1]

4 © UCLES 2009 0654/03/O/N/09 For Examiner's Use 2 Soy beans (soyabeans) are grown for their seeds. The seeds are an excellent source of protein and starch, and are used in the production of a wide variety of foods. (a) Soy beans have nodules on their roots that contain nitrogen-fixing bacteria called Rhizobium. Suggest how this helps soy bean plants to produce seeds containing a lot of protein. [2] (b) Soy beans have been cultivated for hundreds of years, and artificial selection has produced many different varieties. The soy bean plants have been selected to possess a particular set of characteristics, such as providing high yields of seeds. Outline how artificial selection would be carried out to produce a variety of soy beans that produced high yields of seeds. [4] (c) An investigation was carried out to find out how four different varieties of soy beans would be affected if the concentration of carbon dioxide in the atmosphere increased. Four varieties were used, called Arksoy, Dunfield, Mukden and Mandarin. Several plants of each variety were grown in normal concentrations of carbon dioxide. Another set of plants of each variety was grown in a high concentration of carbon dioxide. The mean masses of leaves and seeds produced per plant were measured at each carbon dioxide concentration. The results are shown in Table 2.1.

5 © UCLES 2009 0654/03/O/N/09 [Turn over For Examiner's Use Table 2.1 variety feature at normal carbon dioxide concentration at high carbon dioxide concentration mass of leaves per plant / g 6.54 7.75 Arksoy mass of seeds per plant / g 30.8 42.4 mass of leaves per plant / g 7.20 11.19 Dunfield mass of seeds per plant / g 46.1 55.9 mass of leaves per plant / g 6.08 8.93 Mukden mass of seeds per plant / g 41.4 56.5 mass of leaves per plant / g 5.43 7.30 Mandarin mass of seeds per plant / g 31.3 58.4 (i) State which variety of soy bean would be best to grow at normal carbon dioxide concentration. [1] (ii) State which variety of soy bean showed the greatest increase in seed production at high carbon dioxide concentration compared with normal carbon dioxide concentration. [1] (iii) Explain why the mass of leaves and seeds per plant was greater at high carbon dioxide concentration than at normal carbon dioxide concentration. [2] (iv) Suggest and explain why it is important to find out how crops grow in carbon dioxide concentrations that are greater than in our present atmosphere. [2]

6 © UCLES 2009 0654/03/O/N/09 For Examiner's Use 3 Some types of fertiliser have the letters NPK on the package label, indicating the chemical symbols of three elements contained in the fertiliser. N : P : K (a) State and explain which of the elements shown in the name NPK contains atoms that have their electrons arranged as shown in Fig. 3.1. Fig. 3.1 element explanation [2] (b) Plants need nitrogen in order to produce amino acids. Name the three elements, other than nitrogen, which are present in all amino acid molecules. [1]

7 © UCLES 2009 0654/03/O/N/09 [Turn over For Examiner's Use (c) Ammonia is an important compound that is used in the manufacture of fertilisers. Fig. 3.2 shows a simplified diagram of the type of reaction vessel that is used in the production of ammonia. nitrogen mixture of gases containing 15 % by mass of ammonia (the yield of ammonia = 15 %) hydrogen iron catalyst Fig. 3.2 (i) The equation below shows what happens on the surface of the iron catalyst. The equation is not balanced. Balance the equation. N2 + H2 NH3 [1] (ii) The yield of ammonia in this reaction vessel is 15%. This means that the mixture of gases coming out of the reaction vessel contains 15% by mass of ammonia. State and explain which gases account for most of the remaining 85% of the gas mixture. [2]

8 © UCLES 2009 0654/03/O/N/09 For Examiner's Use (iii) Research chemists and engineers have investigated the effects of temperature and pressure on the yield of ammonia. Fig 3.3 shows the results of their investigations. 100 80 60 40 20 0 0 200 400 600 800 1000 200 °C 400 °C 600 °C pressure / atmospheres yield of ammonia % Fig. 3.3 The engineers running the factory want to increase the yield of ammonia. Use the information in Fig. 3.3 to suggest two ways in which this could be done. 1 2 [2] (d) In an ammonia factory, 1000 kg of gas mixture leave the reaction vessel every minute. In this factory the yield of ammonia is 17 %. Calculate the number of moles of ammonia which leave the reaction vessel every minute. Show your working. [relative atomic masses, Ar : N=14; H=1] 1 kg = 1000 g [4]

9 © UCLES 2009 0654/03/O/N/09 [Turn over For Examiner's Use 4 (a) Humans, like all mammals, keep their body temperature fairly constant. (i) Explain how a body temperature that is much higher than normal could affect the chemical reactions that take place in the body. [3] (ii) Explain how sweating helps to cool the body. [2] (b) A gene has recently been discovered which affects the ability to smell a particular component of male sweat. The gene has two alleles. Allele A is dominant and causes the ability to smell this substance. Allele a is recessive, and causes inability to smell it. Construct a complete genetic diagram to show the expected genotypes and phenotypes in the offspring of two parents who are both heterozygous for these alleles. [4]

10 © UCLES 2009 0654/03/O/N/09 For Examiner's Use 5 (a) Fig. 5.1 shows some apparatus set up to measure the specific heat capacity of aluminium. power supply heater aluminium block insulation water thermometer joulemeter Fig. 5.1 The block is heated electrically and the electrical energy input is measured using a joulemeter. The temperature of the block and the total electrical energy supplied are measured at intervals. The results are shown on Fig. 5.2. 0 10 20 30 40 50 60 70 50 40 30 20 10 0 temperature / °C energy supplied / kJ Fig. 5.2

11 © UCLES 2009 0654/03/O/N/09 [Turn over For Examiner's Use (i) State the relationship between the temperature and the energy supplied. [1] (ii) Use the graph to calculate the energy needed to raise the temperature of the block from 25 °C to 45 °C. Show your working on the graph. [2] (iii) The mass of the aluminium block is 2 kg. Use the formula energy = mass x specific heat capacity x temperature change to calculate the specific heat capacity of aluminium. Show your working. [3] (iv) The temperature of the block rose from 25 °C to 45 °C in 600 seconds. Use your answer from (ii) to calculate the electrical power during this time. State the formula that you use and show your working. formula working [2]

12 © UCLES 2009 0654/03/O/N/09 For Examiner's Use (v) The voltage of the power supply in Fig. 5.1 is 12 V. It is fitted with a 10 amp fuse. Use the formula power = voltage x current to explain why this fuse is adequate for this experiment. [2] (b) A thin sheet of aluminium is placed between a radioactive source and a radiation detector. The source emits one type of radiation only. The radiation detected is reduced but not completely stopped. (i) Suggest which type of radiation is being emitted and explain your answer. [2] (ii) A thin sheet of another metal will completely stop this type of radiation. Suggest what this metal could be. [1]

13 © UCLES 2009 0654/03/O/N/09 [Turn over For Examiner's Use 6 The Earth’s crust contains very large amounts of the elements silicon and aluminium. These elements are found combined in compounds such as silicon dioxide and aluminium oxide. (a) Pure silicon is used in the manufacture of many types of electronic devices. Silicon can be obtained by heating a mixture of silicon dioxide and carbon. A symbolic equation for this reaction is shown below. SiO2 + C → Si + CO2 State the type of chemical reaction shown above. Explain your answer briefly. [2] (b) Fig. 6.1 shows a diagram of the process used to extract aluminium from aluminium compounds. A simplified equation for what happens in this electrolysis reaction is shown below. aluminium oxide → aluminium + oxygen – + molten aluminium collects here molten electrolyte containing aluminium compounds Fig. 6.1 (i) Explain why aluminium atoms are formed at the cathode and not at the anode. [2]

14 © UCLES 2009 0654/03/O/N/09 For Examiner's Use (ii) Describe what happens to convert aluminium ions into aluminium atoms on the surface of the cathode. [2] (c) Silicon dioxide and aluminium oxide are found together in clay. When some types of clay are shaken with water, a colloid is produced. Fig. 6.2 shows a diagram of how such a mixture might look when magnified. dispersed clay particles water Fig. 6.2 Explain, in terms of rays of light, why a colloid is not transparent, but an aqueous solution of sodium chloride is transparent. [2]

15 © UCLES 2009 0654/03/O/N/09 [Turn over For Examiner's Use (d) Table 6.1 shows some information about carbon dioxide and silicon dioxide. Table 6.1 carbon dioxide silicon dioxide chemical formula CO2 SiO2 type of bonding covalent covalent melting point / °C – 57 1710 Explain, in terms of their internal structures, why much more energy is needed to melt silicon dioxide than to melt carbon dioxide. [2]

16 © UCLES 2009 0654/03/O/N/09 For Examiner's Use 7 Fig. 7.1 shows the main bones, muscles and tendons in the human arm. A B C D hinge joint at elbow triceps biceps tendons tendons Fig. 7.1 (a) Name bones A, B, C and D. A B C D [2] (b) Describe the roles of each of the following structures in helping to make the arm bend at the elbow. (i) biceps muscle [2] (ii) tendons [1]

17 © UCLES 2009 0654/03/O/N/09 [Turn over For Examiner's Use (c) Muscles are able to produce quite large forces, but they cannot change their length by very much. Use this information, and the principle of levers, to explain why the biceps muscle is attached to bone C close to the elbow joint, and not further away from it. [3] (d) Blood is supplied to muscles in capillaries. (i) Explain why a muscle such as the biceps needs a good supply of blood. [3] (ii) Describe one way in which the structure of a capillary is related to its function. structure how this relates to its function [2]

18 © UCLES 2009 0654/03/O/N/09 For Examiner's Use 8 (a) (i) An elephant of mass 4000 kg is moving at 0.5 m / s. Calculate the momentum of the elephant. State the formula that you use and show your working. formula working [2] (ii) Two elephants, both of mass 4000 kg and both travelling at a speed of 0.5 m / s, collide head on. Explain what happens to their momentum, energy and speed. momentum energy speed [3] (b) An elephant lifts a mass of 300 kg through a vertical distance of 2 m. Calculate the work done by the elephant. State the formula that you use and show your working. formula working [2]

19 © UCLES 2009 0654/03/O/N/09 [Turn over For Examiner's Use (c) (i) To determine the density of an elephant, its volume must be measured. Describe a method for measuring the volume of an irregularly shaped object. [2] (ii) The volume of an elephant is 4 m3. Its mass is 4000 kg. Calculate the density of this elephant. State the formula that you use and show your working. formula working [2] (d) Elephants can communicate using infra-sound. These sound waves have frequencies as low as 5 Hz. The audible range for an elephant is 5 Hz – 10 000 Hz. (i) What is meant by the term frequency? [1] (ii) State the audible range for humans. [1] (iii) Sound waves are longitudinal waves. Explain how these differ from transverse waves. [2]

20 © UCLES 2009 0654/03/O/N/09 For Examiner's Use 9 Fig. 9.1 shows a process carried out at an oil refinery. refinery gas gasoline naphtha diesel oil fuel oil bitumen petroleum Fig. 9.1 (a) State one way in which the properties of gasoline are different from those of diesel oil. [1] (b) Gasoline (petrol) is used as car fuel. (i) Name a poisonous carbon compound which is found in the exhaust gases from cars. [1] (ii) Describe briefly how the amount of this gas entering the air is reduced in modern cars. [1]

21 © UCLES 2009 0654/03/O/N/09 [Turn over For Examiner's Use (c) Alkenes are unsaturated hydrocarbons produced by the catalytic cracking of alkanes from petroleum (crude oil). (i) Complete the graphic (displayed) formulae for the alkane and the alkene which have three carbon atoms per molecule. ALKANE ALKENE H C H H H C H H [2] (ii) The apparatus in Fig. 9.2 can be used to test a gaseous hydrocarbon to discover whether it is an alkane or an alkene. Name solution X and describe what would be observed if the gaseous hydrocarbon is an alkene. gaseous hydrocarbon solution X Fig. 9.2 [2]

22 © UCLES 2009 0654/03/O/N/09 For Examiner's Use (d) Ethanol, C2H6O, is an important chemical which is made from ethene, C2H4, in the presence of a catalyst. Write a balanced symbolic equation for the conversion of ethene to ethanol. [1] (e) Fuel oil is used as an energy source in some power stations. Fuel oil which is obtained from petroleum contains sulfur compounds. In some power stations, the combustion products from the burning of fuel oil are treated with calcium hydroxide, an alkali, before release into the atmosphere. Suggest and explain why this is done. [3]

24 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2009 0654/03/O/N/09 Group 140 Ce Cerium 58 141 Pr Praseodymium 59 144 Nd Neodymium 60 Pm Promethium 61 150 Sm Samarium 62 152 Eu Europium 63 157 Gd Gadolinium 64 159 Tb Terbium 65 162 Dy Dysprosium 66 165 Ho Holmium 67 167 Er Erbium 68 169 Tm Thulium 69 173 Yb Ytterbium 70 175 Lu Lutetium 71 232 Th Thorium 90 Pa Protactinium 91 238 U Uranium 92 Np Neptunium 93 Pu Plutonium 94 Am Americium 95 Cm Curium 96 Bk Berkelium 97 Cf Californium 98 Es Einsteinium 99 Fm Fermium 100 Md Mendelevium 101 No Nobelium 102 Lr Lawrencium 103 1 H Hydrogen 1 7 Li Lithium 3 23 Na Sodium 11 24 Mg Magnesium 12 40 Ca Calcium 20 45 Sc Scandium 21 48 Ti Titanium 22 51 V Vanadium 23 52 Cr Chromium 24 55 Mn Manganese 25 56 Fe Iron 26 59 Co Cobalt 27 59 Ni Nickel 28 64 Cu Copper 29 65 Zn Zinc 30 70 Ga Gallium 31 27 Al Aluminium 13 11 B Boron 5 12 C Carbon 6 14 N Nitrogen 7 16 O Oxygen 8 19 F Fluorine 9 28 Si Silicon 14 31 P Phosphorus 15 32 S Sulfur 16 35.5 Cl Chlorine 17 40 Ar Argon 18 20 Ne Neon 10 4 He Helium 2 73 Ge Germanium 32 75 As Arsenic 33 79 Se Selenium 34 80 Br Bromine 35 84 Kr Krypton 36 39 K Potassium 19 88 Sr Strontium 38 89 Y Yttrium 39 91 Zr Zirconium 40 93 Nb Niobium 41 96 Mo Molybdenum 42 Tc Technetium 43 101 Ru Ruthenium 44 103 Rh Rhodium 45 106 Pd Palladium 46 108 Ag Silver 47 112 Cd Cadmium 48 115 In Indium 49 119 Sn Tin 50 122 Sb Antimony 51 128 Te Tellurium 52 127 I Iodine 53 131 Xe Xenon 54 137 Ba Barium 56 139 La Lanthanum 57 * 178 Hf Hafnium 72 181 Ta Tantalum 73 184 W Tungsten 74 186 Re Rhenium 75 190 Os Osmium 76 192 Ir Iridium 77 195 Pt Platinum 78 197 Au Gold 79 201 Hg Mercury 80 204 Tl Thallium 81 207 Pb Lead 82 209 Bi Bismuth 83 Po Polonium 84 At Astatine 85 Rn Radon 86 Fr Francium 87 227 Ac Actinium 89 9 Be Beryllium 4 I II III IV V VI VII 0 85 Rb Rubidium 37 133 Cs Caesium 55 226 Ra Radium 88 The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). a X b a = relative atomic mass X = atomic symbol b = proton (atomic) number Key *58-71 Lanthanoid series 90-103 Actinoid series DATA SHEET The Periodic Table of the Elements

© UCLES 2009 UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the October/November 2009 question paper for the guidance of teachers 0654 CO-ORDINATED SCIENCES 0654/03 Paper 3 (Extended Theory), maximum raw mark 100 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes must be read in conjunction with the question papers and the report on the examination. • CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the October/November 2009 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Page 2 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2009 0654 03 © UCLES 2009 1 (a) angles approx correct ; angles of incidence and reflection correctly labelled ; arrow on reflected ray and straight lines ; [3] (b) (i) violet / blue / indigo ; [1] (ii) different wavelengths (frequencies) ; [1] [Total: 5] 2 (a) bacteria / Rhizobium, use nitrogen (from the air) ; to make, ammonium / nitrogen compounds ; (ignore nitrates) fixed nitrogen / nitrogen compound, used for making, amino acids / proteins ; [max 2] (b) choose, plants / soy beans, that have, high yields of seeds ; or choose one plant with high yield of seeds and another with other good characteristic ; breed them together ; select the offspring with highest yields ; repeat over many generations ; [max 4] (c) (i) Dunfield ; [1] (ii) Mandarin ; [1] (iii) more photosynthesis ; so more production of, carbohydrates / named carbohydrate /materials for making cells ; carbon dioxide is a limiting factor at normal concentrations ; [max 2] (iv) carbon dioxide in the atmosphere is increasing ; ref to a reason for this, e.g. burning fossil fuels / deforestation ; idea of needing to plan for future food production ; [max 2] [Total: 12]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2009 0654 03 © UCLES 2009 3 (a) phosphorus / P ; (15 electrons so) 15 protons so atomic number 15 / proton number is 15 or 5 electrons in outer shell / in group 5, and, three shells / period 3 ; [2] (b) carbon hydrogen oxygen / C H O ; [1] (c) (i) N2 + 3H2 2NH3 ; [1] (ii) nitrogen and hydrogen ; reversible reaction / have not reacted ; [2] (iii) use high pressure / at or above 200 ; use low temperature / 200 °C ; [2] (d) Mr of ammonia = 17 ; mass of ammonia exiting reactor per minute = 1000 × 17/100 = 170 kg ; = 170 000 g ; moles of ammonia = 170 000 / 17 = 10 000 ; [4] [Total: 12] 4 (a) (i) would affect enzymes ; if temperature rises much above, 37 / 40 °C ; ref. to denaturing them / altering their shape / destroying them ; enzymes catalyse (metabolic) reactions ; without enzymes reactions will not take place ; [3 max] (ii) evaporation ; of water (in sweat) ; ref. to latent heat of evaporation ; heat taken from skin ; [2 max] (b) parents Aa × Aa ; each produce gametes A and a ; offspring shown as AA, Aa, Aa and aa ; AA and Aa can smell, aa cannot smell ; ratio is 3 can smell : 1 cannot smell ; accept fraction or percentage [4 max] [Total: 9]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2009 0654 03 © UCLES 2009 5 (a) (i) temperature rise directly proportional to energy input or temperature (rise) proportional to energy input ; [1] (ii) working ; 40 kJ ; [2] (iii) working 40/2 × 20 ; ecf from (ii) = 1 ; ecf if 2000 used in calculation kJ / kg °C ; can work in joules throughout – ensure units in answer are appropriate [3] (iv) power = energy / time ; 40 000/600 = 66.7/67 W ; ecf from (iii) [2] (v) current = 66.7/12 = 5.5 A ; ecf from (iv) so fuse will not, melt / blow / break ; [2] (b) (i) beta ; alpha would be completely stopped and gamma not stopped at all ; [2] (ii) lead ; [1] [Total: 13] 6 (a) reduction / oxidation / redox ; Si / SiO2 has lost oxygen and is reduced / carbon has gained oxygen and is oxidised ; [2] (b) (i) aluminium ions are positive ; and are attracted to the negative (cathode) ; [2] (ii) aluminium ions gain electrons ; gain three electrons (each) / are discharged ; [2] (c) light rays are, scattered / reflected, by dispersed solid in solution ; light rays pass through solution (unaffected) ; [2] (d) carbon dioxide is simple molecular ; melting involves breaking weak forces between molecules ; (max 1) silicon dioxide is giant (lattice) ; melting involves breaking very many strong bonds between atoms ; (max 1) [2] [Total: 10]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2009 0654 03 © UCLES 2009 7 (a) A scapula / shoulder bone B humerus C radius D ulna any two correct for one mark ; [2] (b) (i) contracts / gets shorter ; pulls, lower arm / forearm / ulna / radius, up ; [2] (ii) transmit, force / pull, from muscle to bone ; [1] (c) biceps exerts a turning force ; elbow is, fulcrum / pivot ; moment is force × distance from pivot ; large force small distance from pivot can balance small force large distance from pivot ; small, contraction / movement, of biceps causes large movement of hand ; if distance from elbow was greater then, turning force would be greater / less force would be needed ; but muscle would need to get much shorter ; [max 3] (d) (i) supply of oxygen ; supply of, nutrients / glucose ; for respiration ; energy needed for contraction ; [max 3] (ii) (very) small / narrow ; brings blood close to all cells ; thin walls / walls only one cell thick ; allows (rapid) movement of, substances / named substances (between cells and blood) ; large surface area to volume ratio ; allows (rapid) movement of, substances / named substances (between cells and blood) ; [max 2] 8 (a) (i) (momentum) = m × v ; = 4000 × 0.5 = 2000 kg m / s ; [2] (ii) total momentum is conserved / momentum equals zero ; energy is lost to environment / sound / heat ; speed (of each) becomes zero ; [3] (b) (work done =) force × distance ; = 3000 × 2 = 6000 J ; [2]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2009 0654 03 © UCLES 2009 (c) (i) immerse in water ; measure volume of liquid displaced ; [2] (ii) (density =) mass / volume ; = 4000 / 4 = 1000 kg / m3 ; [2] (d) (i) the number of waves per, second / unit time ; [1] (ii) 20 Hz – 20 000 Hz ; allow from 10 Hz up to 26 000 Hz [1] (iii) longitudinal - pattern of disturbance is in same direction as direction of wave (movement) / ref. compressions and rarefactions ; transverse - pattern of disturbance is at right angles to direction of wave (movement) ; [2] [Total: 15] 9 (a) gasoline has: lower viscosity / lower boiling point / lower melting point / less coloured / higher flammability / less dense / more volatile ; [1] (b) (i) carbon monoxide ; [1] (ii) use of catalytic (converter) ; [1] (c) (i) ALKANE ALKENE H C H H H H H H C C H H C H H H H C C H [2] (ii) X is bromine / bromine solution / bromine water / potassium manganate(VII) solution ; if hydrocarbon is an alkene then bromine changes from orange to colourless / manganate(VII) from purple to colourless ; [2] (d) C2H4 + H2O → C2H6O ; [1] (e) sulfur dioxide is produced (when sulfur compounds burn) ; ref. acid rain ; acidic gases / sulfur compounds, react with calcium hydroxide ; ref. neutralisation ; [max 3] [Total: 11]