Cambridge IGCSE Science - Combined 0653 — 2014 Oct/Nov Paper 2 · Variant 1

This document consists of 20 printed pages. DC (CW/AR) 89391/3 © UCLES 2014 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education * 4 4 0 2 3 4 4 4 5 5 * COMBINED SCIENCE 0653/21 Paper 2 (Core) 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 20. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question.

2 0653/21/O/N/14 © UCLES 2014 1 Party lights add light and colour to festive occasions. A set of party lights has five lamps connected in series with a switch and a battery. (a) Complete the circuit diagram using standard circuit symbols for this set of party lights. [2] (b) Each lamp in the set is labelled 1.2 V, 0.1 A. (i) The term ‘1.2 V’ gives important information about the lamp. Explain why this information is important for the use of the lamp in a circuit. … … …[2]

3 0653/21/O/N/14 © UCLES 2014 [Turn over (ii) Use the formula resistance = potential difference current to calculate the resistance of one lamp. resistance = … Ω [1] (iii) Calculate the total resistance of the set of five lamps. total resistance = …Ω [1] (iv) State the name of the unit of resistance whose symbol is Ω. … [1]

4 0653/21/O/N/14 © UCLES 2014 2 Gasoline is a product obtained from petroleum (crude oil) following fractional distillation. (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 order in which the processes occur. Fig. 2.1 [2] (b) Gasoline and diesel oil are different mixtures of compounds called hydrocarbons. A hydrocarbon is a compound of the elements hydrogen and carbon. Table 2.1 gives four descriptions of materials. Use the words compound, element and mixture to complete Table 2.1. You can use each of the words once, more than once or not at all. Table 2.1 material description can be found in the Periodic Table cannot be broken down into simpler substances contains different types of molecules only contains molecules which are identical but each molecule contains more than one type of atom [4]

5 0653/21/O/N/14 © UCLES 2014 [Turn over (c) The hydrocarbons present in gasoline and diesel oil are alkanes. (i) State a use that gasoline and diesel oil have in common. …[1] (ii) State the chemical property of alkanes that make them suitable for this use. …[1] (d) Refinery gas is another product obtained from petroleum. Refinery gas contains methane and propane. (i) The chemical formula of methane is CH4. State the products of the complete combustion of methane. …[2] (ii) Propane contains molecules in which carbon atoms and hydrogen atoms are bonded in the ratio 3:8. Deduce the chemical formula for propane. chemical formula for propane = … [1]

6 0653/21/O/N/14 © UCLES 2014 3 (a) A balanced diet for a person contains all the food groups in the correct amounts. Fig. 3.1 shows some food substances needed in a balanced diet. (i) Using straight lines connect the food substance with their correct functions. One has been done for you. food substance function vitamin D growth and repair carbohydrate needed in small amounts to make parts of the body fat needed in small amounts to prevent rickets protein storing energy calcium and iron providing energy as a fuel Fig. 3.1 [3] (ii) All diets should contain fibre. Describe the role of fibre in the body. … …[1]

7 0653/21/O/N/14 © UCLES 2014 [Turn over (b) Fig. 3.2 shows two meals. Jill works in an office all day and is 15 kg overweight compared to the average weight for her height. In the evenings Jill sits and reads books and watches television. meal 1 fried fish and fried potato, can of lemonade meal 2 pasta with cheese sauce, lettuce and tomato, milk Fig. 3.2 (i) Give two reasons why meal 2 would be more suitable than meal 1 for Jill to eat on a regular basis. reason 1 … … reason 2 … … [2] (ii) Suggest one other food that Jill could add to meal 1 that would make it more healthy. Explain your choice. … … …[1]

8 0653/21/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 tap to allow acid to be added slowly conical flask 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 0653/21/O/N/14 © UCLES 2014 [Turn over (iii) Explain why a neutral solution is formed when she adds the acid to the alkali. … … …[2] (b) (i) The student repeats part (a) in order to prepare a colourless neutral solution of potassium chloride. She changes the method from that 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. … … …[2] (ii) Describe how a sample of crystals of potassium chloride could be produced from the solution obtained in (b)(i). … …[1]

10 0653/21/O/N/14 © UCLES 2014 5 (a) Fig. 5.1 shows two cells X and Y which were taken from different areas of the same leaf. cell X cell Y B A Fig. 5.1 (i) State the names of cell parts A and B. A … B … [2] (ii) 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 cells came from. Explain your answer below. … … …[3]

11 0653/21/O/N/14 © UCLES 2014 [Turn over (iii) The leaf was then tested with iodine solution for the presence of starch. 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 (iv) Explain why only parts of the leaf show the presence of starch. … …[1] (b) In humans, starch in food is digested by the enzyme amylase. The action of amylase starts when food is present in the mouth cavity. (i) Explain why amylase stops working after the food is swallowed and it reaches the acidic conditions of the stomach. … … …[2] (ii) Name one organ in the body which produces digestive enzymes. …[1]

12 0653/21/O/N/14 © UCLES 2014 6 (a) Fig. 6.1 shows an aircraft at rest on an airport runway waiting to take off. The engines are running, but the pilot is using the brakes to prevent it moving. The diagram shows four forces, labelled P, Q, R and S, acting on the aircraft as it waits to take-off. S Q R P Fig. 6.1 (i) State which force from P, Q, R and S is the weight of the aircraft … the thrust of the engines … the force of the brakes … [2] (ii) Explain, in terms of balanced forces, why the aircraft remains at rest. … … …[2] (b) (i) State the form of energy carried by the aircraft in its fuel tanks. …[1] (ii) The aircraft takes off and climbs. The energy in the aircraft’s fuel is transferred to the aircraft as it takes off and climbs. Identify the two useful forms of energy that the aircraft has gained. … and …[2]

13 0653/21/O/N/14 © UCLES 2014 [Turn over (iii) Identify one form of energy produced by the aircraft that is not useful. …[1] (c) On the axes below, sketch a distance / time graph for the aircraft as it cruises at a constant speed. distance time [1]

14 0653/21/O/N/14 © UCLES 2014 7 (a) Fig. 7.1 shows the carbon cycle. carbon dioxide in the air photosynthesis grass fossil fuels death death decomposers eating eating rabbit respiration fox Fig. 7.1 (i) Describe the importance of respiration in the carbon cycle. … …[1] (ii) Give the word equation for respiration. + + [2] (iii) In Fig. 7.1 find a food chain containing three organisms and write the food chain in the space below. [2]

15 0653/21/O/N/14 © UCLES 2014 [Turn over (iv) Decomposers are organisms found in the soil. Suggest the role of the decomposers in the carbon cycle shown in Fig. 7.1. … … …[2] (b) (i) With reference to Fig. 7.1 explain why the amount of carbon dioxide in the air is increased by coal-fired factories, … … the removal of large amounts of grass. … …[2] (ii) Describe how increased carbon dioxide levels could affect the environment. … …[1]

16 0653/21/O/N/14 © UCLES 2014 8 (a) Complete the sentences below using words from this list: You may use each word once, more than once or not at all. drops boils energy evaporates infra-red molecules ultraviolet The Earth is warmed by … radiation from the Sun. After it has rained, the Sun’s heat … water on the ground, and the ground dries as water … escape from the water surface. [3] (b) Fig. 8.1 shows a thermometer containing mercury which is taken from a dark room into bright sunlight. 0 10 20 30 40 50 60 70 80 90 100 °C 0 10 20 30 40 50 60 70 80 90 100 °C in dark room in bright sunlight Fig. 8.1 Explain, in terms of particles, why the level of mercury in the thermometer goes up. … … …[2]

17 0653/21/O/N/14 © UCLES 2014 [Turn over (c) The Sun emits many different frequencies of electromagnetic radiation including visible light, infra-red, ultra-violet and X-rays. Complete Table 8.1 to show the types of electromagnetic radiation emitted by the Sun. Table 8.1 highest frequency lowest frequency gamma radiation microwaves radio waves [3] (d) The Sun produces sound waves as well as electromagnetic radiation. Explain why we cannot hear any sound from the Sun. … … …[2]

18 0653/21/O/N/14 © UCLES 2014 9 A student performs an experiment to extract copper by heating copper oxide on a carbon block. Fig. 9.1 shows the apparatus he uses. burner copper oxide carbon block start of experiment end of experiment layer of copper Fig. 9.1 (a) The copper oxide reacts with the carbon. (i) Write a chemical word equation for the reaction between copper oxide and carbon. + + [2] (ii) Explain why this reaction is an example of a redox reaction. … … …[2] (b) After the experiment the student tries to remove the copper from the block. He pours dilute hydrochloric acid into the hole in the block. Predict whether or not the hydrochloric acid will remove the copper. Explain your answer by referring to the reactivity series. … … …[2]

19 0653/21/O/N/14 © UCLES 2014 (c) Impurities in the copper oxide can produce sulfur dioxide gas when it is heated. Sulfur dioxide forms a strongly acidic solution when it dissolves in water. Describe how the environment is damaged by sulfur dioxide gas. … … … …[3]

20 0653/21/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 0653/21 Paper 2 (Core 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 21 © Cambridge International Examinations 2014 1 (a) circuit symbols correct ; circuit connected correctly with 5 lamps (allow ±1) ; [2] (b) (i) gives p.d. required to light the lamp (for normal use) / what battery to use to make lamp work / to drive correct current ; don’t exceed stated p.d. or may blow lamp / too high current (owtte) ; [2] (ii) R = 1.2 / 0.1 = 12 (Ω) ; [1] (iii) Total resistance = 5 × 12 = 60 (Ω) ; allow ecf [1] (iv) ohm ; [1] [Total: 7] 2 (a) B C ; (B C) D A ; [2] (b) material description element can be found in the Periodic Table element cannot be broken down into simpler substances mixture contains different types of molecules compound only contains molecules which are identical but each molecule contains more than one type of atom ; ; ; ; [4] (c) (i) fuels ; [1] (ii) flammable ; [1] (d) (i) carbon dioxide ; water ; [2] (ii) C3H8 ; [1] [Total: 11]

Page 3 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 21 © Cambridge International Examinations 2014 3 (a) (i) (all 4 correct = 3 marks, 3 correct = 2 marks, 2 or 1 correct = 1 mark) [3] (ii) prevents constipation ; [1] (b) (i) meal 2 is balanced / meal 1 is not balanced / not enough vitamin C/D / not enough fibre / not enough iron / calcium ; meal 1 contains too much fat / carbohydrate / energy ; Jill does not need so much energy in food because of her lifestyle ; [max 2] (ii) e.g. apple (no mark) adds fibre / vitamins C/D ; or milk (no mark) adds calcium / vitamins C/D ; or any food (no mark) and valid point that addresses the reasons mentioned in (b)(i) ; [1] [Total: 7] 4 (a) (i) initial any between 8 and 14 final 7 ; [1] (ii) initial violet / purple final green ; [1] (iii) neither acid nor alkali in excess ; (chemical) reaction / neutralisation ; Ref. to acid has pH<7 / low pH ; [max 2] (b) (i) repeat without indicator ; using same volumes of solutions ; [2] (ii) evaporation / heating to remove water ; [1] [Total: 7] vitamin D carbohydrate fat protein calcium and iron growth and repair needed in small amounts to make parts of the body needed in small amounts to prevent rickets storing energy providing energy as a fuel

Page 4 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 21 © Cambridge International Examinations 2014 5 (a) (i) A cell membrane ; B vacuole ; [2] (ii) X label line to green area and Y label line to white area ; green color contained in chloroplasts ; which are only present in cell X ; or white area does not contain chlorophyll / chloroplasts ; which are absent from cell Y ; [3] (iii) black/blue black or shaded area matching green area of leaf and labelled black ; [1] (iv) chlorophyll / chloroplasts needed to make starch / for photosynthesis / to trap light ; [1] (b) (i) enzyme is denatured ; not the optimum pH for the enzyme ; [2] (ii) pancreas / salivary glands / small intestine / stomach ; [1] [Total: 10] 6 (a) (i) weight of the aircraft: R ; thrust of the engines: Q and force of the brakes S (both needed, correct way round) ; [2] (ii) thrust and braking force equal and opposite ; unbalanced forces needed to move / accelerate (the aircraft) ; [2] (b) (i) chemical (energy) [1] (ii) kinetic (energy) ; gravitational / potential (energy) ; [2] (iii) heat / sound ; [1] (c) [1] [Total: 9] distance time

Page 5 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 21 © Cambridge International Examinations 2014 7 (a) (i) returns carbon / carbon dioxide back to air / produces carbon dioxide from sugar / glucose ; [1] (ii) sugar / glucose + oxygen → carbon dioxide + water [2] LHS ; RHS ; (iii) grass → rabbit → fox / grass → rabbit → decomposer ;; [2] (1 mark for correct organisms in right order, 1 mark for correct arrows) (iv) feed on dead / decaying bodies / waste ; release carbon / carbon dioxide back to the air ; during respiration ; [max 2] (b) (i) combustion / burning of fossil fuels (produces carbon dioxide) ; reduces carbon dioxide removal by photosynthesis; [2] (ii) (increases) global warming / description of consequences ; [1] [Total: 10] 8 (a) infra-red ; evaporates ; molecules ; [3] (b) mercury absorbs energy (from Sun) / mercury expands as temperature increases ; mercury particles move faster / mercury particles get further apart ; [2] (c) higher frequency lower frequency gamma radiation X-rays ultraviolet visible infra-red microwave radio waves any one in its correct box ; second one in correct box ; third and fourth in correct boxes ; [3] (d) sound needs medium to travel through / can’t travel through a vacuum / empty space ; region between Sun and Earth is a vacuum ; [2] [Total: 10]

Page 6 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 21 © Cambridge International Examinations 2014 9 (a) (i) copper oxide + carbon → copper + carbon dioxide LHS ; RHS ; [2] (ii) copper oxide (loses oxygen so) is reduced ; carbon (gains oxygen so) is oxidised ; [2] (b) no reaction (between copper and dilute hydrochloric acid) ; copper is below hydrogen in the reactivity series ; [2] (c) (sulfur dioxide) dissolves in rain / atmospheric water / forms acid rain ; collects in lakes / rivers etc. ; damages plants / animals ; effect of gas on respiratory system ; other correct ; [max 3] [Total: 9]