Cambridge IGCSE Science - Combined 0653 — 2014 Oct/Nov Paper 3 · Variant 1

This document consists of 21 printed pages and 3 blank pages. DC (SJF/CGW) 89403/3 © UCLES 2014 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education * 5 3 5 7 1 6 9 2 7 9 * COMBINED SCIENCE 0653/31 Paper 3 (Extended) October/November 2014 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. 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 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.

2 0653/31/O/N/14 © UCLES 2014 1 Party lights add light and colour to festive occasions. A set of party lights has a switch and a battery connected to five lamps in parallel. The battery consists of four cells in series. (a) Draw the circuit diagram using standard circuit symbols for this set of party lights. [2]

3 0653/31/O/N/14 © UCLES 2014 [Turn over (b) The p.d. across the battery of four cells is 6 V. (i) Each lamp in the set is labelled 6 V, 0.5 A. Find the current from the source required to light this set of lamps. current from source = … A [1] (ii) Use your answer to (i) to calculate the total resistance of the set of lights. State the formula that you use and show your working. formula working total resistance = … Ω [2] (c) Most sets of party lights have lamps that are connected in parallel but some sets are connected in series. State what happens to the set of lights if one lamp breaks when the lamps are connected in series, … parallel. …[1]

4 0653/31/O/N/14 © UCLES 2014 2 Gasoline and petroleum jelly are products obtained from petroleum (crude oil) following fractional distillation at an oil refinery. (a) Statements A to D below describe the processes which occur during fractional distillation to produce gasoline. The processes have been written in the wrong order. A gasoline vapour condenses into a liquid at its boiling point B petroleum mixture is heated in a furnace C vapour mixture enters the fractionating column D vapour mixture rises and cools In the boxes in Fig. 2.1 write the letters A to D to show the correct order of the processes. Fig. 2.1 [2] (b) A process called cracking is also carried out at an oil refinery. Fig. 2.2 shows the apparatus used to demonstrate the cracking of petroleum jelly. aluminium oxide powder strong heat gentle heat petroleum jelly mineral wool plug oil bromine solution Fig. 2.2 Petroleum jelly is gently heated until it melts and then boils. The vapour passes over aluminium oxide powder, which is strongly heated. The gas formed reacts with bromine solution. An oil forms on top of the bromine solution.

5 0653/31/O/N/14 © UCLES 2014 [Turn over (i) State the function of the aluminium oxide. …[1] (ii) Explain, in terms of collisions of reacting particles, why the aluminium oxide is powdered. … … …[2] (iii) List petroleum jelly, diesel oil and refinery gas in order of their boiling points. highest boiling point … … lowest boiling point … [1] (iv) List petroleum jelly, diesel oil and refinery gas in order of the average length of their molecules. longest molecules … … shortest molecules … [1] (v) State the relationship between boiling point and length of molecules. Explain your answer. … … …[2]

6 0653/31/O/N/14 © UCLES 2014 3 (a) If a person does not eat a balanced diet, they can suffer from malnutrition. (i) Use straight lines to match the effects of malnutrition to their causes. One line is drawn for you. effect of malnutrition cause obesity not enough fibre in the diet constipation taking in much more energy than the body needs coronary heart disease taking in less energy than the body needs starvation taking in too much animal fat and salt [2] (ii) A person has constipation. Suggest one food that may be missing from their diet and explain how this food prevents constipation. food … explanation … …[2] (iii) Obese people are extremely overweight because they are taking in more energy than they need. Suggest one food an obese person should avoid eating regularly and explain your answer. food … explanation … …[1]

7 0653/31/O/N/14 © UCLES 2014 [Turn over (b) Taking exercise is recommended for people who are overweight. A survey was carried out to compare the amounts of exercise taken by two groups of people. The first group was made up from people of normal weight and the second group was made up from overweight people. Each group contained 100 men and women. The survey determined how many people took exercise at least twice a week. To count as exercise, an activity had to raise a person’s heart rate for at least 20 minutes. The results are shown in Fig. 3.1. 0 10 20 30 40 number of people who exercised at least twice a week normal weight overweight 50 60 70 men women Fig. 3.1 (i) Use the information in Fig. 3.1 to compare the level of exercise people did in terms of their sex, … … their weight. … …[2] (ii) Suggest why there is not enough evidence in the survey to conclude that exercise prevents people from being overweight. … … …[2]

8 0653/31/O/N/14 © UCLES 2014 4 (a) A student investigates the neutralisation reaction between hydrochloric acid and potassium hydroxide. Fig. 4.1 shows the apparatus she uses. dilute hydrochloric acid conical flask tap to allow acid to be added slowly potassium hydroxide solution and indicator Fig. 4.1 She adds full range indicator (Universal Indicator) solution to the potassium hydroxide solution. Potassium hydroxide solution is alkaline. She slowly adds some dilute hydrochloric acid to the potassium hydroxide solution until the solution in the flask is neutral. The colour of the indicator changes as she adds the acid. Fig. 4.2 shows how the colour of the indicator changes with pH. pH 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 colour RED ORANGE GREEN BLUE PURPLE Fig. 4.2 (i) State the initial and final values of the pH of the solution in the flask. initial … final … [1] (ii) State the initial and final colour of the indicator in the solution in the flask. initial … final … [1]

9 0653/31/O/N/14 © UCLES 2014 [Turn over (b) The reaction between hydrochloric acid and potassium hydroxide forms potassium chloride. (i) Complete the balanced chemical equation for the reaction. KOH + HCl … [2] (ii) The student repeats part (a) in order to prepare a colourless sample of crystals of potassium chloride. She changes the method described in part (a) slightly, using information obtained from the first time she carried out the experiment. Describe the change in method and explain how she uses the results of her first experiment. … … … …[3] (c) The melting point of crystals of potassium chloride is 770 °C. Explain, in terms of the forces between particles, why potassium chloride forms crystals with a high melting point. … … … …[2]

10 0653/31/O/N/14 © UCLES 2014 5 (a) Fig. 5.1 shows cells X and Y which were taken from different areas of the same leaf. cell X cell Y Fig. 5.1 Fig. 5.2 shows a leaf similar to the one from which these cells were taken. white green Fig. 5.2 On Fig. 5.2, use label lines and the letters X and Y to show where these leaf cells came from. Explain your answer below. … … …[2]

11 0653/31/O/N/14 © UCLES 2014 [Turn over (b) The leaf in Fig. 5.2 was then tested with iodine solution for the presence of starch. (i) On Fig. 5.3 draw the result of the starch test on this leaf. Label the leaf with the colours that are observed in different areas. [1] Fig. 5.3 (ii) Explain why only parts of the leaf show the presence of starch. … … … …[3] (c) In humans, starch is digested by the enzyme amylase which starts its action while food is in the mouth cavity. Explain in detail why amylase stops working after the food is swallowed and reaches the acidic conditions in the stomach. … … … …[3]

12 0653/31/O/N/14 © UCLES 2014 6 (a) Fig. 6.1 shows an aircraft accelerating along the airport runway. The aircraft, fully loaded, has a total mass of 205 000 kg. The diagram shows four forces, labelled P, Q, R and S, acting on the aircraft as it moves along the runway before taking off. S Q R P Fig. 6.1 (i) State two forces from P, Q, R and S that are equal and opposite while the aircraft accelerates along the airport runway. … and … [1] (ii) State which force from P, Q, R and S is the result of a gravitational field acting on the mass of the aircraft and give the name of this force. … …[2]

13 0653/31/O/N/14 © UCLES 2014 [Turn over (iii) On the axes below, sketch a distance / time graph for the aircraft as it moves along the runway from rest to take-off. distance time [1] (b) The aircraft takes off and climbs to a height of 5000 m. The chemical energy in the aircraft’s fuel is transferred to the aircraft as it takes off and climbs. (i) State two useful forms of energy gained by the aircraft as a result of this transfer. … and … [1] (ii) The forms of energy in (b)(i) add up to less energy than the energy transferred from the fuel. The principle of energy conservation applies to the energy transferred from the fuel. State what happens to the remainder of the energy from the fuel. …[1]

14 0653/31/O/N/14 © UCLES 2014 (c) When the aircraft levels out at a height of 5000 m, it has burned some fuel and now has a reduced total mass of 200 000 kg. The aircraft flies at constant speed of 720 km / hr. (i) Calculate the speed of the aircraft in metres per second. speed = … m / s [1] (ii) Use your answer from (c)(i) to calculate the kinetic energy of the aircraft. State the formula you use and show your working. formula working kinetic energy = … J [2]

15 0653/31/O/N/14 © UCLES 2014 [Turn over 7 (a) Fig. 7.1 shows the carbon cycle. carbon dioxide in the air photosynthesis combustion fossil fuels death death X eating eating sheep wild cat respiration Fig. 7.1 (i) The sheep eats a plant leaf. A carbon atom from the starch in this leaf enters the air shortly after the leaf is eaten. Describe a possible pathway taken by the carbon atom. Explain your answer fully. … … … … …[3] (ii) The organisms labelled X are found in the soil. Describe in detail the role these organisms play in the carbon cycle. … … … …[3]

16 0653/31/O/N/14 © UCLES 2014 (b) (i) With reference to Fig. 7.1 and your own knowledge, state two ways in which the burning of fossil fuels can change the composition of the gases in the atmosphere. 1 … 2 …[2] (ii) Suggest one way in which the environment can be harmed by one of the changes you have stated in part (b)(i). … …[1]

17 0653/31/O/N/14 © UCLES 2014 [Turn over 8 The Sun emits many different frequencies of electromagnetic radiation including visible light, infra- red, ultra-violet and X-rays. (a) (i) State the meaning of the term frequency. … …[1] (ii) Complete Table 8.1 to show the types of electromagnetic radiation emitted by the Sun. Table 8.1 highest frequency lowest frequency gamma radiation visible light microwaves radio waves [2] (b) After rain has fallen, puddles of water are left on the ground. When the Sun shines, it warms the air and the water in the puddles and dries the ground. (i) Complete the following sentences about the forces and distances between molecules, using words or phrases. When the Sun warms the water in a puddle on the ground, the water expands because the water molecules … . When the water expands, the forces between the molecules … . As the air above the puddle gets warmer, the molecules in the air move … . [3]

18 0653/31/O/N/14 © UCLES 2014 (ii) Use your answers to (b)(i) to explain why the Sun dries the ground. … … …[2] (c) The Sun produces sound waves as well as electromagnetic radiation. (i) Explain why we cannot hear any sound from the Sun. … …[2] (ii) It takes eight minutes for the visible light emitted from the Sun to travel to the Earth. Suggest how long it would take for a burst of X-rays emitted by the Sun to travel to the Earth. Give a reason for your answer. … …[1]

19 0653/31/O/N/14 © UCLES 2014 [Turn over 9 (a) The Thermite reaction occurs between aluminium and iron oxide powders. It is an example of a redox reaction. Fig. 9.1 shows how a furnace in which the Thermite reaction is occurring can be used to repair a broken steel rail. furnace iron oxide and aluminium broken steel rail Fig. 9.1 The Thermite reaction produces molten iron that runs down into the broken rail and welds (joins) the ends together. (i) State the type of chemical reaction that causes the temperature to increase. …[1] (ii) State the energy transfer occurring during the reaction. … … [1] (iii) The word equation for the Thermite reaction is shown below. aluminium + iron oxide aluminium oxide + iron Explain why the Thermite reaction is an example of a redox reaction. … … …[2]

20 0653/31/O/N/14 © UCLES 2014 (iv) Aluminium ore contains aluminium oxide. A student suggests that metallic iron could be used to extract aluminium from its ore. State whether or not this would work. Explain your answer by referring to the information contained in part (a)(iii). … … …[2] (b) In industry, aluminium is extracted from aluminium oxide by electrolysis. Fig. 9.2 shows the apparatus used. molten mixture containing aluminium oxide molten aluminium carbon cathode lining the electrolysis cell carbon anode + – Fig. 9.2 (i) Aluminium is deposited on the cathode. Describe, by referring to the movement of ions and electrons, how these aluminium atoms are formed. … … …[2] (ii) Name the other substance formed by this electrolysis process. …[1]

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24 0653/31/O/N/14 © UCLES 2014 Group The Periodic Table of the Elements 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 91 238 231 147 237 244 243 247 247 251 252 257 258 259 260 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 82 209 209 210 222 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 55 226 223 Ra Radium 88 a X b a = relative atomic mass X = atomic symbol b = atomic (proton) number Key DATA SHEET * 58–71 Lanthanoid series † 90–103 Actinoid series The volume of one mole of any gas is 24dm3 at room temperature and pressure (r.t.p.). Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every 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. 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.

® IGCSE is the registered trademark of Cambridge International Examinations. CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International General Certificate of Secondary Education MARK SCHEME for the October/November 2014 series 0653 COMBINED SCIENCE 0653/31 Paper 3 (Extended Theory), maximum raw mark 80 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2014 series for most Cambridge IGCSE®, Cambridge International A and AS Level components and some Cambridge O Level components.

Page 2 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 31 © Cambridge International Examinations 2014 1 (a) symbols all correct ; circuit connected correctly (allow ±1 cell or lamp) ; [2] (b) (i) 5 × 0.5 = 2.5 (A) ; [1] (ii) (R =) V/I (or words) ; = 6 / 2.5 = 2.4 (Ω) ; [2] (c) series: all bulbs go out AND parallel: rest of bulbs stay alight ; [1] [Total: 6] 2 (a) B C ; (B C) D A ; [2] (allow 1 mark if both B and A are correctly located) (b) (i) catalyst ; [1] (ii) increases rate / frequency of collision of particles ; increases speed of reaction / increases surface area (of catalyst) ; [2] (iii) (petroleum) jelly (diesel) oil (refinery) gas in order ; [1] (iv) (petroleum) jelly (diesel) oil (refinery) gas in order ; [1]

Page 3 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 31 © Cambridge International Examinations 2014 obesity constipation coronary heart disease effect of malnutrition starvation not enough fibre in the diet taking in more energy than the body needs taking in less energy than the body needs cause taking in too much animal fat and salt (v) the higher the boiling point the longer / larger the molecules ; reference to greater / stronger intermolecular forces ; [2] (allow reference to intermolecular bonds) [Total: 9] 3 (a) (i) correctly completed diagram ;; [2] (3 correct = 2 marks, 2 or 1 correct = 1 mark) (ii) example of fruit or vegetable containing fibre ; provides bulk to propel food through the intestines ; [2] (iii) any food rich in carbohydrate or fat / carbohydrate or fat (no mark) reference to reducing energy intake / avoiding the carbohydrate or fat content of the stated food ; [1] (b) (i) more females than males / fewer males than females took exercise ; more normal weight than obese / fewer obese than normal weight took exercise ; [2] (ii) reference to small sample size ; reference to the lack of information about variables that should be controlled (if the study were to be extended) ; reference to the need for information gathered over a longer time period ; [max 2] [Total: 9]

Page 4 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 31 © Cambridge International Examinations 2014 4 (a) (i) initial between 8 and 14 to 7 (final) ; [1] (ii) purple / blue to green ; [1] (b) (i) KCl ; H2O ; [2] (ii) repeat without indicator / use pH meter / use indicator paper ; using same volume(s) of solution(s) ; evaporate (the water from the neutral mixture) / heat (the solution) then cool ; [3] (c) reference to the involvement of ions / ionic compound / particles with opposite charges ; the idea of strong forces / bonds between particles that must be broken / ions must be separated ; (breaking bonds / separating ions) requires a large amount of energy ; [max 2] [Total: 9] 5 (a) X label line to green area and Y label line to white area ; green area containing chlorophyll / chloroplasts only in cell X / white area does not contain chlorophyll /chloroplasts shown in cell Y ; [2] (b) (i) black or shaded in area matching green area of leaf and indicated as black ; [1] (ii) chlorophyll / chloroplasts traps light energy ; for photosynthesis ; which makes (glucose / sugar which leads to ) starch ; [3] (c) acid denatures enzyme ; no longer optimum pH / owtte ; changes shape of enzyme / active site / substrate no longer fits active site ; [3] [Total: 9]

Page 5 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 31 © Cambridge International Examinations 2014 6 (a) (i) P and R ; [1] (ii) R ; (R) is the weight ; [2] (iii) [1] (ignore whether curve becomes linear or continues to curve) (b) (i) gravitational / potential energy and kinetic energy ; (both required) [1] (ii) (rest of energy transferred to) heat / sound ; [1] (c) (i) (720 × 1000) ÷ 3600 / 200 (m/s) ; [1] (OR 200 × 3600/1000 = 720 km/h ) (ii) (KE =) ½ m v2 ; = ½ × 200 000 × 200 × 200 = 4 000 000 000(J) ; [2] (allow ecf from (c)(i) ) (allow answers in kJ or MJ provided unit is stated) [Total: 9] 7 (a) (i) starch digested to glucose / sugar ; (glucose / sugar) absorbed and taken to cells (of sheep) ; (glucose broken down by) respiration ; (respiration produces ) carbon dioxide / carbon dioxide breathed out into the air ; [max 3] (allow reference to respiration and exhalation in the wild cat) (allow correct reference to the formation and release of methane) (ii) decomposers ; feed on dead / decaying organisms / feed on waste from organisms ; release carbon / carbon dioxide (into the air) ; by respiration ; [max 3]

Page 6 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 31 © Cambridge International Examinations 2014 (b) (i) increases level of carbon dioxide / carbon monoxide ; reduces oxygen level ; increases sulfur dioxide level ; [max 2] (ii) carbon dioxide: (increases) global warming / described consequence e.g. changed rainfall patterns / floods and or droughts ; sulfur dioxide: causes acid rain / described consequence e.g. chemical weathering of structures / damage to trees or aquatic organisms ; reference to harmful effects in relation to breathing ; (allow other valid answers) [max 1] [Total: 9] 8 (a) (i) number of vibrations / waves per second / unit of time ; [1] (ii) highest frequency lowest frequency (gamma radiation) X-rays ultra- violet (visible light) infra-red (microwaves) (radio waves) all three correctly named ; and in correct positions ; [2] (allow 1 mark if two are correctly named and located) (b) (i) move further apart / increase distance between them ; decrease / weaken / get less ; quicker / more rapidly / faster / further apart ; [3] (ii) infra-red radiation (from Sun warms water) ; (energy from sun) absorbed by water (molecules) ; which move faster / gain kinetic energy. ; forces between molecules are weakened / broken ; (molecules) evaporate / leave the (liquid) surface / turn to gas / vapour ; [max 2] (c) (i) sound is a longitudinal wave ; sound needs medium to travel through ; space is a vacuum / owtte ; [max 2] (ii) 8 minutes / the same time / they travel at the same speed, because all electromagnetic waves travel at the same speed through space / vacuum ; [1] [Total: 11]

Page 7 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 31 © Cambridge International Examinations 2014 9 (a) (i) exothermic ; [1] (ii) chemical (potential) → thermal / heat / kinetic ; [1] (iii) aluminium (gains oxygen and) is oxidised ; iron (oxide) (loses oxygen and) is reduced ; [2] (allow correct references to electron gain by iron and electron loss from aluminium) (iv) iron will not react with / reduce aluminium oxide ; iron is lower in the reactivity series / less reactive than aluminium ; [2] (b) (i) cations / aluminium ions migrate / move / are attracted to the cathode / negative electrode ; electrons flow on to ions / ions gain electrons ; the idea that the ions are discharged as the result of electron gain ; [max 2] (ii) oxygen ; [1] [Total: 9]