Cambridge IGCSE Science - Combined 0653 — 2014 Oct/Nov Paper 3 · Variant 2

This document consists of 23 printed pages and 1 blank page. DC (SJF/CGW) 89404/4 © UCLES 2014 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education * 4 2 3 3 1 6 9 8 3 1 * COMBINED SCIENCE 0653/32 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 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.

2 0653/32/O/N/14 © UCLES 2014 1 Fig. 1.1 is a diagram of the blast furnace used to extract iron from iron ore. hot air blast waste gases waste gases iron ore, coke and limestone hot air blast molten slag molten iron Fig. 1.1 (a) Table 1.1 lists the raw materials used in the furnace. Choose words or phrases from the list to show which chemical substance is provided by each raw material used in the blast furnace. Complete Table 1.1 by writing your choices in the right hand column. You may use each term once, more than once or not at all. calcium carbonate calcium silicate carbon carbon dioxide iron iron oxide nitrogen oxygen Table 1.1 raw material chemical substance iron ore coke air limestone [2]

3 0653/32/O/N/14 © UCLES 2014 [Turn over (b) (i) The word equations for two of the reactions occurring in the furnace are shown below. carbon + oxygen X X + carbon carbon monoxide Name substance X. … [1] (ii) The word equation for ano ther reaction occurring in the furnace is shown below. iron oxide + carbon monoxide iron + carbon dioxide Explain why this reaction is an example of a redox reaction. … … …[2] (iii) Carbon dioxide produced by a blast furnace escapes into the atmosphere. Describe how the addition of carbon dioxide to the atmosphere is affecting the environment. … … …[2] (c) An iron nail is placed into some blue copper sulfate solution. (i) Describe the observations that provide evidence that a chemical reaction is occurring. … … …[2] (ii) Explain the observations in (i) in terms of the particles reacting and formed. … … …[2]

4 0653/32/O/N/14 © UCLES 2014 2 Fig 2.1 shows a special bicycle used to break the speed record for a human-powered bicycle. Fig. 2.1 (a) The rider sets a new speed record of 135 km / h. Calculate the rider’s speed in metres per second (m / s). speed = …m / s [2] (b) The record-breaking run has three stages. Stage 1: the rider accelerates the bicycle from rest for the first 500 m. Stage 2: he maintains a constant speed for the next 200 m. Stage 3: he applies the brakes to slow the bicycle for the last 300 m. The acceleration is not constant, but the braking involves constant deceleration to rest. On the axes below, complete the sketch of the speed / time graph for this record-breaking run. speed time [3]

5 0653/32/O/N/14 © UCLES 2014 [Turn over (c) Throughout the run, the cyclist exerts a constant force to move the bicycle against the opposing forces. (i) Identify the stage in the run during which the driving force of the cyclist is greater than the opposing forces. Give a reason for your answer. … …[1] (ii) Complete the sequence of energy transfers that occurs during the run. … energy in the rider … energy of the bicycle and rider … energy during braking [2]

6 0653/32/O/N/14 © UCLES 2014 3 (a) Fig. 3.1 shows the human gas exchange system. B A Fig. 3.1 Name structures A and B. A … B … [2]

7 0653/32/O/N/14 © UCLES 2014 [Turn over (b) Fig. 3.2 shows an alveolus where gas exchange takes place in the lungs. air alveolus capillary carbon dioxide oxygen Fig. 3.2 Describe two features of the alveolus visible in Fig. 3.2 that adapt it for gaseous exchange. 1 … … 2 … …[2]

8 0653/32/O/N/14 © UCLES 2014 (c) A student investigates his breathing before and after exercise. He measures the number of breaths taken during one minute. He also measures the average volume of one breath during this minute. His results are shown in Table 3.1. Table 3.1 number of breaths per minute average volume of one breath / dm3 total volume of air breathed per minute / dm3 at rest 20 10 immediately after exercise 35 1.2 (i) Calculate the average volume of one breath at rest, volume = … dm3 the total volume of air breathed per minute immediately after exercise. volume = … dm3 [2] (ii) Explain fully why the changes in breathing rate and volume (depth) are needed by the body during exercise. … … … …[3]

9 0653/32/O/N/14 © UCLES 2014 [Turn over 4 Fig. 4.1 shows the circuit symbols for an electric bell and a push-switch. Fig. 4.1 (a) (i) Draw a circuit diagram for a circuit for a battery-powered door-bell with a push-switch for the front door of a house. Label the switch ‘front door’. [2] (ii) The owner of the house wishes the bell to be rung either from the front door or from the back door. Add to your circuit diagram in (i) a second push-switch for the back door. Use the label ‘back door’ to label the second push-switch. [1]

10 0653/32/O/N/14 © UCLES 2014 (b) The ringing bell emits a sound of frequency 400 Hz. (i) State the meaning of the term frequency. … …[1] (ii) The speed of sound in air is 330 m / s. Calculate the wavelength of the sound made by the bell in air. State the formula you use and show your working. formula working wavelength = … m [2] (c) The bell uses four 1.5 V cells. When the push-switch is on, and the bell is ringing, there is a current of 2 A. (i) Calculate the resistance of the bell. State the formula you use, show your working and state the unit of your answer. formula working resistance = … unit … [3]

11 0653/32/O/N/14 © UCLES 2014 [Turn over (ii) A visitor arrives at the door and rings the bell for 10 seconds. Calculate the electrical energy transferred by the bell in 10 seconds. State the formula you use, show your working and state the units of your answer. formula working energy = … unit … [3]

12 0653/32/O/N/14 © UCLES 2014 5 (a) An atom of the element silicon has a proton number 14 and nucleon number 28. (i) Complete Table 5.1 to show the structure of this silicon atom. Table 5.1 in nucleus outside nucleus number of protons number of neutrons number of electrons [2] (ii) Use the Periodic Table to predict how many electrons are in the outer shell of a silicon atom. Describe how you made your prediction. … … …[2] (b) (i) Draw a diagram showing the arrangement of the outer electrons of the atoms bonded in a methane molecule, CH4. [2] (ii) Write a balanced symbol equation for the complete combustion of methane in air. …[2]

13 0653/32/O/N/14 © UCLES 2014 [Turn over 6 Fig. 6.1 shows a method that uses solar energy to purify drinking water. The method is used in hot desert countries. The impure water is heated by the sun and distilled. The pure water is collected separately, while the impurities are left behind. drops of pure water clear plastic cover black-painted base impure water flow Fig. 6.1 (a) (i) State the part of the Sun’s electromagnetic spectrum that heats the water. …[1] (ii) The impure water flows down over a black-painted base. Explain why a black-painted base is used. … …[1] (b) Solar energy produces water vapour from the impure water. Explain in terms of water molecules why heating the impure water produces water vapour. … … …[2]

14 0653/32/O/N/14 © UCLES 2014 (c) Fig. 6.2 shows a ray of sunlight incident on the clear plastic cover just before sunset. The refracted ray passes through the plastic. At the lower face of the plastic, part of the ray is reflected and part is refracted. Draw the path of the ray from the point where it reaches the lower face of the plastic. clear plastic cover lower face of plastic Fig. 6.2 [3]

15 0653/32/O/N/14 © UCLES 2014 [Turn over 7 Fig. 7.1 shows what happens when a plant is placed near a window where bright light is coming from one side. DWVWDUW DIWHUDIHZGD\V OLJKW OLJKW Fig. 7.1 (a) Name the response shown by the plant. …[1]

16 0653/32/O/N/14 © UCLES 2014 (b) The response shown in Fig. 7.1 is caused by plant hormones called auxins which are produced at the tip of the shoot of the plant. A student sets up three experiments using young shoots. In two experiments a lamp produces light from one side. Some shoots have pieces of plastic inserted into their stems. Table. 7.1 shows the shoots at the start and after a few days. Table 7.1 shoot X shoot X shoot Y shoot Y shoot Z light at the start after a few days light in the dark in the dark plastic light light shoot Z plastic plastic plastic (i) Explain fully what causes the response shown by shoot X. … … … …[3]

17 0653/32/O/N/14 © UCLES 2014 [Turn over (ii) Explain why there is no response shown by shoot Y. … …[1] (iii) Shoot Z has grown less than shoot X but has bent in the same direction. Explain these two observations. … … … …[2] (c) Hormones are also present in animals. An example is adrenaline. Adrenaline is secreted into the blood when an athlete starts to run a race. Suggest how this helps the athlete to run fast. … … …[2]

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19 0653/32/O/N/14 © UCLES 2014 [Turn over 8 (a) Table 8.1 shows physical properties of some substances. Table 8.1 substance solubility in water boiling point / °C ethanol soluble 78 potassium nitrate soluble decomposes on heating sodium chloride soluble 1413 water – 100 zinc carbonate insoluble decomposes on heating Some mixtures of these substances and some methods that could be used to separate them are shown below. mixture method of separation zinc carbonate from zinc carbonate and water crystallisation potassium nitrate from potassium nitrate and water distillation water from sodium chloride and water filtration ethanol from ethanol and water fractional distillation Draw straight lines to connect each mixture with the most suitable method of separating the underlined substance. [2]

20 0653/32/O/N/14 © UCLES 2014 (b) Some types of ink are made from different combinations of dyes dissolved in water. The dyes must not be toxic because they are used in colouring pens for children. Fig. 8.1 shows a chromatogram used to test if three inks A, B and C contain a toxic dye X. dye X ink A ink B ink C Fig. 8.1 (i) Describe and explain the procedure used to obtain this chromatogram. You may draw a diagram to support your description. … … … …[3]

21 0653/32/O/N/14 © UCLES 2014 [Turn over (ii) State which ink(s) must not be used in the colouring pens. …[1] (iii) Explain your answer to (ii). … …[1]

22 0653/32/O/N/14 © UCLES 2014 9 (a) Fig. 9.1 shows how the emission of acidic gases from a power station can lead to the formation of acid rain. acidic gases river acid rain Fig. 9.1 (i) State how the acidic gases are produced in the power station. … …[1] (ii) The water in the river becomes acidic. Describe how this could have resulted from the power station’s activities. … … …[2]

23 0653/32/O/N/14 © UCLES 2014 (b) A scientist is concerned about the acidity of the river and the effect it might have on living organisms. The scientist found ten species of animal that lived in local rivers. He looked up how many of these species were able to live in water of different pH values. The results are shown in Fig. 9.2. 0 2 4 6 8 number of species that can live 3.5 4.0 4.5 5.0 pH 5.5 6.0 6.5 10 Fig. 9.2 The pH of the river near the factory varies between pH 4.5 and 6.0. (i) Suggest two reasons why the pH of the river varies. 1 … … 2 … …[2] (ii) Use the information in Fig. 9.2 to find how many of the species studied would be able to survive the changes in pH of the river. Explain your answer. number of species … … …[2] (iii) The acid in the water may enter the cells of the animals living in the river. Suggest how this may affect the enzymes in their cells. Explain your answer. … … …[2]

24 0653/32/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 0653/32 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 32 © Cambridge International Examinations 2014 1 (a) iron oxide carbon oxygen calcium carbonate ;; (1 mark for 2 or 3 correct, 2 marks for 4 correct) [2] (b) (i) carbon dioxide ; [1] (ii) iron (oxide loses oxygen) and is reduced ; carbon (monoxide gains oxygen) and is oxidised ; [2] (allow correct reference to electron transfer) (iii) carbon dioxide is a greenhouse gas / increases the greenhouse effect / reference to global warming ; description of how greenhouse effect operates ; the idea that climates could change / example of one consequence of climate change ; [max 2] (c) (i) brown / pink / copper (coloured) deposit ; blue colour fades / becomes greener ; temperature increase / change ; [max 2] (ii) copper ions become atoms ; iron atoms became ions ; (reaction occurs) because iron higher in reactivity series than copper ; [max 2] [Total: 11]

Page 3 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 32 © Cambridge International Examinations 2014 2 (a) 135 km / hr = 135 000 m / hr ; 135 000 m / hr = 135 000 / 60 × 60 m / s = 37.5 (m / s) ; [2] (b) curved line from origin to level out at horizontal (allow any reasonable shape of curve) ; horizontal line in middle of graph ; straight line descending to meet time axis ; [3] (c) (i) (stage 1 / first 500 m) no mark reference to acceleration occurring (in this stage) / acceleration requires a resultant / unbalanced (driving) force ; [1] (ii) chemical (potential) energy in the rider ; kinetic energy of the bicycle and rider ; heat / thermal / sound energy during braking ; [max 2] (2 marks for 3 correct, 1 mark for 2 correct) [Total: 8] 3 (a) A trachea ; B bronchiole ; [2] (b) large surface (area) ; thin cells in alveoli (and blood capillaries) ; good blood supply ; [max 2] (c) (i) 0.5 (dm3) ; 42 (dm3) ; [2] (ii) faster rate of respiration ; for muscle contraction ; more oxygen needed / oxygen needed more quickly ; need to get rid of more carbon dioxide / need to remove carbon dioxide more quickly ; [max 3] [Total: 9]

Page 4 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 32 © Cambridge International Examinations 2014 4 (a) (i) correct use of circuit symbols ; complete functioning circuit ; [2] (ii) correctly placed second switch in parallel to first switch ; [1] (b) (i) number of vibrations per unit time ; [1] (ii) v = fλ / (λ =) v/f ; = 330 / 400 = 0.825 / 0.83 (m) ; [2] (c) (i) (R =) V / I ; = 4 × 1.5 / 2 = 3 ; ohms / Ω ; [3] (ii) (E =) V I t / I2 R t; = 6 × 2 × 10 / 22 × 3 × 10 = 120 ; joules / J ; [3] [Total: 12]

Page 5 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 32 © Cambridge International Examinations 2014 5 (a) (i) in nucleus outside nucleus number of protons 14 0 / blank number of neutrons 14 0 / blank number of electrons 0 / blank 14 1 mark for each column ;; [2] (ii) 4 ; number of electrons in outer shell shown by group number / owtte ; [2] (b) (i) 4 shared pairs ; atoms correctly labelled with symbols ; (max 1 mark if valence electrons ≠ 8) [2] (ii) CH4 + 2O2 → CO2 + 2 H2O all correct formulae ; then correctly balanced ; [2] [Total: 6] 6 (a) (i) infra-red ; [1] (ii) good absorber (of radiation) ; [1] (b) molecules / particles move faster / gain more (kinetic) energy ; faster /more energetic molecules escape (from liquid) / evaporate ; [2] (c) refracted emergent ray bent away from normal ; angle of reflection equal to angle of incidence (by inspection) ; emergent ray parallel to original incident ray (by inspection) ; [3] [Total: 7]

Page 6 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 32 © Cambridge International Examinations 2014 7 (a) phototropism ; [1] (b) (i) auxins move across stem / move to shaded side ; cause cell elongation (on shaded side) ; more growth on shaded side / reference to differential growth (between lit and shaded sides) ; [3] (ii) auxins cannot move back from tip / through plastic ; [1] (iii) growth is less in the absence of light / owtte ; auxins prevented from moving on one side / auxins cannot reach the right side / owtte ; [2] (c) increase in blood glucose ; increase in pulse / heart rate / blood pressure ; for increased metabolic activity / rate of respiration ; [max 2] [Total: 9] 8 (a) all correct 2 marks, 3 or 2 correct 1 mark ;; [2] zinc carbonate from zinc carbonate and water potassium nitrate potassium nitrate and water water from sodium chloride and water crystallisation distillation filtration ethanol from ethanol and water fractional distillation

Page 7 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2014 0653 32 © Cambridge International Examinations 2014 (b) (i) (marks may be awarded from a combination of words with a clear diagram) solutions spotted on / added to (chromatography) paper / the line / origin ; paper suspended in water / solvent with spots above the solvent ; spots move up the paper (with the water/solvent) / reference to distance moved related to solubility ; [3] (ii) A and C ; [1] (iii) both produce spots at same position as dye X / owtte ; [1] [Total: 7] 9 (a) (i) burning / combustion of (fossil) fuels / burning material that produces sulfur / nitrogen oxides ; [1] (ii) acid gases carried by the wind ; react with / dissolve in (rain) water (to form acid rain) ; (acid) rain falls on land/river / drains into river ; [max 2] (b) (i) rate of water flow into the river may vary ; variation in amount and location of rainfall ; variation in factory working / energy requirements ; variation in wind speed and direction ; may get pollutants from other sources (which themselves change pH) ; [max 2] (marks can also be awarded for other valid reasons) (ii) 3 ; all animals needing a higher pH than 4.5 would not survive ; [2] (iii) enzymes will not function as well / will not be at optimum ; enzymes may be denatured / simple description of denaturation in terms of molecular shape change ; [2] [Total: 9]