Cambridge IGCSE Science - Combined 0653 — 2013 Oct/Nov Paper 3 · Variant 3

This document consists of 23 printed pages and 1 blank page. IB13 11_0653_33/3RP © UCLES 2013 [Turn over *8316460039* UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMBINED SCIENCE 0653/33 Paper 3 (Extended) October/November 2013 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a pencil for any diagrams 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. 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. www.XtremePapers.com

2 © UCLES 2013 0653/33/O/N/13 For Examiner's Use 1 (a) Fig. 1.1 shows a root hair cell. Fig. 1.1 (a) (i) Use the letters A and B to label these parts of the root hair cell in Fig. 1.1. A the structure that controls what enters and leaves the cell B a structure that is not present in animal cells [2] (ii) Describe how the structure of the root hair cell helps it to carry out its functions. [3]

3 © UCLES 2013 0653/33/O/N/13 [Turn over For Examiner's Use (b) Fig. 1.2 shows a leaf stalk from a celery plant in a beaker containing a solution of red dye. pale green leaf leaf stalk red dye Fig. 1.2 After an hour, the veins in the leaf had become red. (i) Suggest why this happened. [2] (ii) The experiment was repeated at a lower temperature. It took longer for the veins in the leaf to become red. Suggest an explanation for this result. [3]

4 © UCLES 2013 0653/33/O/N/13 For Examiner's Use 2 (a) Table 2.1 shows information about some chemical elements and their positions in the Periodic Table. Table 2.1 element group number in the Periodic Table oxygen 6 calcium 2 lithium 1 sulfur 6 fluorine 7 Select two elements from Table 2.1 whose atoms form covalent bonds with each other and explain your answer. and explanation [2]

5 © UCLES 2013 0653/33/O/N/13 [Turn over For Examiner's Use (b) Fig. 2.1 shows the electron arrangement in an atom of phosphorus. P Fig. 2.1 Phosphorus and hydrogen bond together to form the compound phosphine. One molecule of phosphine contains one atom of phosphorus. Predict and explain the chemical formula of one molecule of phosphine. You may wish to draw a diagram to help you to answer this question. predicted formula explanation [3]

6 © UCLES 2013 0653/33/O/N/13 For Examiner's Use (c) A student added excess acidified barium chloride solution to a solution of a magnesium sulfate. Fig. 2.2 shows the procedure followed. solution W precipitate of barium sulfate solution of magnesium sulfate acidified barium chloride solution Fig. 2.2 A white precipitate of barium sulfate was produced. The chemical equation for the reaction is BaCl2(aq) + MgSO4(aq) BaSO4(s) + MgCl2(aq) State three ions that are dissolved in solution W in Fig. 2.2. 1 2 3 [2]

7 © UCLES 2013 0653/33/O/N/13 [Turn over For Examiner's Use (d) Fig. 2.3 shows apparatus used by the student to investigate the reaction between different metals and steam, H2O(g). small test-tube initially filled with water gas collecting water heat steam metal reaction tube delivery tube Fig. 2.3 The student carried out experiments using two metals, P and Q. His results are shown in Table 2.2. Table 2.2 metal product in the reaction tube product in the small test-tube P no reaction no gas produced Q oxide of element Q hydrogen gas Use the observations to compare the reactivities of the three elements P, Q and hydrogen. Explain your answer briefly. most reactive element least reactive element explanation [3]

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9 © UCLES 2013 0653/33/O/N/13 [Turn over For Examiner's Use 3 (a) Fig. 3.1 shows a circuit used to measure the current passing through a resistor when the voltage across it is changed. A V Fig. 3.1 Complete the sentences below using suitable words. When the voltage across the resistor is reduced, the current through the resistor . When the voltage of the supply is reduced, the voltage across the resistor . [1] (b) The resistance of a piece of wire depends on a number of variables such as the temperature of the wire and the material from which it is made. State two other factors which affect the resistance of a piece of wire. 1 2 [2]

10 © UCLES 2013 0653/33/O/N/13 For Examiner's Use (c) Fig. 3.2 shows a circuit used to power a small motor. A V M Fig. 3.2 The voltage across the motor is 3 V. The current through the motor is 0.6 A. (i) Calculate the power input to the motor. State the formula that you use, show your working and state the unit of your answer. formula working unit [2] (ii) The motor is able to lift a load of 40 N through 1.2 m in 36 seconds. Calculate the power output of the motor. State the formula that you use, show your working and state the unit of your answer. formula working unit [3]

11 © UCLES 2013 0653/33/O/N/13 [Turn over For Examiner's Use (iii) Explain why there is a difference between your answers to (i) and (ii). [1] (iv) Calculate the efficiency of the motor. Show your working. [2]

12 © UCLES 2013 0653/33/O/N/13 For Examiner's Use 4 Soya beans are an important crop in Brazil. Soya beans can be used to make soya 'milk', which can be made into yoghurt. (a) To make yoghurt, microorganisms are added to soya milk. The milk is then kept warm for several hours. (i) State the type of microorganism that is added to milk to make yoghurt. [1] (ii) Explain why the milk is kept warm for several hours. [2] (b) Researchers in Brazil investigated whether adding sugar to the soya milk affected the yoghurt that was produced. They added sugar to one batch of soya milk, but not to another. They measured the percentage of lactic acid in each batch of yoghurt at the start, and after 4, 5, 6 and 7 hours. Fig. 4.1 shows their results. 0 1 2 3 time / hours 4 5 6 7 0.5 0.4 0.3 0.2 0.1 0 percentage of lactic acid no added sugar no added sugar no added sugar with added sugar with added sugar with added sugar Fig. 4.1

13 © UCLES 2013 0653/33/O/N/13 [Turn over For Examiner's Use (i) Describe the change in lactic acid concentration during the fermentation of the yoghurt with no added sugar. [2] (ii) Compare the concentration of lactic acid when sugar is added with the concentration of lactic acid when when no sugar is added. State the difference and explain it. [2] (c) Large areas of rainforest have been cleared in Brazil, to provide more land for growing soya beans. Explain how cutting down the rainforest can harm the environment. [3]

14 © UCLES 2013 0653/33/O/N/13 For Examiner's Use 5 Dilute nitric acid reacts with calcium carbonate according to the equation nitric acid calcium carbonate calcium nitrate carbon dioxide + + water + (a) Fig. 5.1 shows apparatus a student used to investigate the reaction between dilute nitric acid and excess calcium carbonate. dilute nitric acid calcium carbonate Fig. 5.1 Describe how the student could show that this reaction produces carbon dioxide. You may complete the diagram to help you answer this question. [2] (b) A student carried out an investigation into the way that the rate of the reaction between calcium carbonate and nitric acid changed when he varied the concentration of the nitric acid. Fig. 5.2 shows the apparatus the student used to measure the rate of reaction. thermometer side-arm test-tube excess dilute nitric acid calcium carbonate controlled temperature water bath piston of the syringe slides out as gas enters gas syringe Fig. 5.2

15 © UCLES 2013 0653/33/O/N/13 [Turn over For Examiner's Use The student measured the rate of reaction by finding the time it took for the gas syringe to fill with gas. The student measured the rate of reaction using five different concentrations of nitric acid. Fig. 5.3 shows the student’s results as a graph of rate of reaction against acid concentration. concentration of nitric acid rate of reaction 0 0 Fig. 5.3 (i) Describe the relationship shown by the graph. [2] (ii) Explain these results in terms of particle collisions. [2] (iii) Explain why the temperature of the reacting mixture needs to be kept constant. [2]

16 © UCLES 2013 0653/33/O/N/13 For Examiner's Use 6 (a) (i) Fig. 6.1 gives information about the uses of different types of electromagnetic waves and their effects on living tissue. Draw lines to link each electromagnetic wave with its effect on living tissue and its use. One has been completed as an example. screening luggage security marking satellite communication seeing uses X-rays microwave ultra violet visible light type of radiation activates sensitive cells in retina kills cancerous cells heats water in tissues causes tanning of skin effects on tissue Fig. 6.1 [4] (ii) State one property that is the same for all electromagnetic waves. [1] (b) Fig. 6.2 shows a light ray entering an optical fibre. optical fibre light ray Fig. 6.2 The light ray travels all the way through the optical fibre. Explain why the light ray is able to stay inside the optical fibre. You may draw on the diagram if it helps your answer. [2]

17 © UCLES 2013 0653/33/O/N/13 [Turn over For Examiner's Use (c) Fig. 6.3 shows an observer’s eye looking at an object in a mirror. observer’s eye object mirror Fig. 6.3 (i) On Fig. 6.3 complete the ray diagram to show how the two rays of light from the object enter the eye of the observer. [1] (ii) On Fig. 6.3 show how the observer sees rays of light which appear to come from the image behind the mirror. Label the position of the image with an X. [2]

18 © UCLES 2013 0653/33/O/N/13 For Examiner's Use 7 Fig. 7.1 shows the contents of the human thorax (chest). A … B … Fig. 7.1 (a) On Fig. 7.1, name structures A and B. [2] (b) Oxygen diffuses into the blood from the alveoli inside the lungs. (i) Define the term diffusion. [2] (ii) When a person is doing vigorous exercise, the concentration of carbon dioxide in the blood increases. Explain why this happens. [3]

19 © UCLES 2013 0653/33/O/N/13 [Turn over Please turn over for Question 8.

20 © UCLES 2013 0653/33/O/N/13 For Examiner's Use 8 Gasoline and diesel are liquid mixtures of hydrocarbons used as fuels. Fig. 8.1 shows the structure of a typical molecule in gasoline. C H H H C C H H C H H C H C H H H H C H H C H H H H Fig. 8.1 (a) (i) State the chemical formula of the molecule in Fig. 8.1. [1] (ii) Explain briefly why a molecule like the one in Fig. 8.1 is classified as an alkane molecule. [1] (b) Table 8.1 shows some properties of gasoline and diesel. Table 8.1 fuel temperature range over which the fuel boils / °C viscosity (how easily the liquid flows) gasoline 40 to 205 runny (flows easily) diesel 250 to 350 less runny Explain, in terms of molecules and forces, why the properties of these fuels are different. [2]

21 © UCLES 2013 0653/33/O/N/13 [Turn over For Examiner's Use (c) (i) Describe what is observed when gaseous ethene is passed through a solution of bromine. [1] (ii) Name the type of chemical reaction that occurs between bromine and ethene. [1] (iii) Ethene, C2H4, can be made to undergo complete combustion when it reacts with oxygen. Write the balanced symbol equation for the complete combustion of ethene. [3]

22 © UCLES 2013 0653/33/O/N/13 For Examiner's Use 9 Fig. 9.1 shows a solar-powered golf cart used to carry golfers around a golf course. Fig. 9.1 (a) As the cart moves around the course, the motion of the cart is measured. Fig. 9.2 shows a distance / time graph for a small part of the journey lasting 60 seconds. 100 80 60 40 20 0 0 10 20 30 time / s 40 50 60 distance / m A B C D E F E D C B A Fig. 9.2

23 © UCLES 2013 0653/33/O/N/13 For Examiner's Use (i) The speed of the cart between B and C is 5 m / s. The mass of the cart is 400 kg. Calculate the kinetic energy of the cart between B and C. State the formula that you use, show your working and state the unit of your answer. formula working unit [2] (ii) Describe the motion of the cart between D and E. [1] (b) Sometimes the golfer’s hands begin to sweat. Explain in terms of particles how sweating cools his hands by evaporation. [2]

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 2013 0653/33/O/N/13 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

CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the October/November 2013 series 0653 COMBINED SCIENCE 0653/33 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 2013 series for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level components and some Ordinary Level components. www.XtremePapers.com

Page 2 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0653 33 © Cambridge International Examinations 2013 1 (a) (i) A to cell membrane ; B to cell wall / large vacuole ; [2] (ii) functions are uptake of water and mineral ions ; partially permeable membrane allows (water to enter) by osmosis ; has large surface area ; increases (rate of) uptake (of water / mineral ions) ; [max 3] (b) (i) water moved up through the stem / stalk ; through xylem vessels ; reference to transpiration ; description of transpiration ; veins contain xylem vessels ; [max 2] (ii) slower rate of transpiration ; water pulled up xylem / stem / stalk more slowly ; ref. to decrease in rate of evaporation / diffusion, at lower temperature ; particles / water molecules, have less kinetic energy / move more slowly ; [max 3] [Total: 10] 2 (a) two of oxygen sulfur fluorine ; both elements are non-metals / implication of non-metallic character ; [2] (b) PH3; / H3P ; hydrogen atoms have electron configuration of 1 ; atoms share (pairs) of electrons ; so that each has filled shells ; (correct bonding diagram scores max2 of last three points) [max 3] (c) barium, magnesium, chloride,(allow hydrogen) ;; (all 3 for 2 marks any 2 for 1 mark max 1 if sulfate suggested) [2] (d) Q hydrogen P ; Q more reactive than H because able to remove oxygen from it / owtte ; P less reactive than H since unable to separate oxygen from it / owtte ; [3] [Total: 10]

Page 3 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0653 33 © Cambridge International Examinations 2013 3 (a) decreases ; decreases ; [1] (b) length ; diameter ; [2] (c) (i) (power =) voltage x current ; = 3 × 0.6 = 1.8W ; [2] (ii) work = force × distance and power = work/time ; = 40 × 1.2/36 ; 1.33W ; [3] (iii) energy lost (as heat /sound) ; [1] (iv) efficiency = 1.33/1.8 × 100 ; 73.88% / 0.74 ; [2] [Total: 11] 4 (a) (i) bacteria / Lactobacillus / Streptococcus ; [1] (ii) to speed up the production of yoghurt ; microorganisms work faster / better (at higher temperature) ; ref. to optimum temperature for enzymes ; [max 2] (b) (i) increased ; use of data e.g. from 0.15% to 0.31% / by 0.16% ; description of the variation in rate e.g. rate of increase slowed after 6 hours ; [max 2] (ii) added sugar increases the amount of lactic acid / fermentation / rate of reaction / use of data to illustrate this ; (microorganisms) convert sugar to lactic acid ; more sugar increases rate of production of lactic acid ; [max2] (c) area too small to support populations / reduction in biodiversity / extinction / species become endangered / lack of opportunity to find new medicines ; due to reduction of habitat ; flooding / leaching of minerals ; due to rain falling directly on soil / lack of protection of tree canopy / increased runoff ; soil erosion ; due to lack of tree roots ; drought ; due to lack of transpiration by trees to form rain ( leading to desertification) ;

Page 4 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0653 33 © Cambridge International Examinations 2013 CO2 levels in the atmosphere increase ; due to fewer trees to photosynthesise/ less photosynthesis to remove carbon dioxide ; also due to burning trees produce CO2 / rotting trees produce CO2 by respiration of microbes ; carbon dioxide traps long-wave radiation / infra-red / heat / thermal energy /is a greenhouse gas ; reduces rate of loss of heat from the Earth’s surface / increases global warming ; [Total: 11] 5 (a) pass gas into limewater ; goes cloudy / milky / precipitate forms ; [2] (b) (i) the greater the acid concentration the higher the rate ; ref. to direct proportionality ; [2] (ii) ref. to reaction occurring as the result of particle collisions / ref. to the identity of colliding particles ; higher concentration means higher frequency of collision ; [2] (iii) temperature affects rate of reaction ; so control needed so rate investigation data is valid / ref. to fair test ; additional collision theory detail related to rate ; [max 2] [Total: 8] 6 (a) (i) [4] (ii) wave speed ; [1] screening luggage security marking satellite communication seeing uses X-rays microwave ultra violet visible light type of radiation activates sensitive cells in retina kills cancerous cells heats water in tissues causes tanning of skin effects on tissue

Page 5 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0653 33 © Cambridge International Examinations 2013 (b) waves are reflected along fibre ; reference to total internal (reflection) ; angle (of incidence) is greater than critical angle ; no light escapes ; [max 2] (c) (i) two rays reflected at the mirror entering the eye with angles correct by inspection ; [1] (ii) two construction lines drawn back from the mirror locating X ; X labelled in correct position by inspection ; [2] [Total: 10] 7 (a) (i) A trachea ; B lung ; [2] (b) (i) (net) movement of molecules ; from region of high concentration to low concentration / down a concentration gradient ; [2] (ii) more energy used / more muscle contraction ; reference to (more / faster) respiration ; so more carbon dioxide produced (in cells) ; so greater diffusion gradient (from cells to blood) ; [max 3] [Total: 7] 8 (a) (i) C8H18 ; [1] (ii) it is a hydrocarbon containing only single bonds / a saturated hydrocarbon / it conforms to the general formula CnH2n+2 ; [1] (b) molecules in gasoline (on average) are smaller / lighter ; so attractive forces between molecules in gasoline are lower ; so less energy needed to separate molecules (in gasoline) ; so are less entangled (than in diesel) ; [max 2] (c) (i) orange solution becomes colourless ; [1] (ii) addition ; [1] (iii) C2H4 + 3O2 → 2CO2 + 2H2O ;;; [3] (LHS formulae; RHS formulae; then balanced) [Total: 9]

Page 6 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0653 33 © Cambridge International Examinations 2013 9 (a) (i) KE = ½ mv2 ; = ½ × 400 × 5 × 5 = 5000J ; [2] (ii) not moving ; [1] (b) heat transferred from hands / body to sweat / heat absorbed by sweat from golfer’s hands / body/heat energy in hands / body reduced by sweating ; kinetic energy of water molecules increases / water molecules move faster ; faster moving / more energetic (water) molecules escape / leave the surface / water (sweat) molecules turn to gas/vapour ; ref. to break bonds /break forces of attraction between molecules ; (KE) / energy of (remaining) water molecules (in sweat) decreases ; [max 2]