Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2015 Oct/Nov Paper 5 · Variant 3

This document consists of 10 printed pages and 2 blank pages. IB15 11_0654_53/5RP © UCLES 2015 [Turn over *8412478804* For Examiner's Use 1 2 3 Total Cambridge International Examinations Cambridge International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/53 Paper 5 Practical Test October/November 2015 2 hours Candidates answer on the Question Paper. Additional Materials: As listed in the Confidential Instructions. 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 an HB 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. Notes for Use in Qualitative Analysis for this paper are printed on page 12. 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 © UCLES 2015 0654/53/O/N/15 1 Emperor penguins live and breed in the Antarctic. Their average body temperature needs to be maintained at 39 °C but air temperature can fall as low as -40 °C. Penguins often huddle together in groups. You are going to investigate how this behaviour may be beneficial by using test-tubes to represent penguins. (a) Read through the whole of part (b) before you start the experiment. Use the information in part (b) to complete the headings in Table 1.1, including any units. [2] (b) • Place into a large beaker the set of three test-tubes that are held together by a rubber band. This is beaker A. • Place the individual large test-tube into a second beaker. This is beaker B. • Pour some of the hot water provided into each of the four test-tubes to the lines already drawn on them. • Place one thermometer into one of the test-tubes in beaker A and the other one into the test-tube in beaker B. • Measure the temperature to the nearest 0.5 °C of the hot water in A and B. Record the temperatures in Table 1.1 at time 0. • Immediately start the stopclock. • After two minutes measure the temperature in A and B and record these temperatures in Table 1.1. Repeat this at two minute intervals for 10 minutes. Table 1.1 0 2 4 6 8 10 [5] (c) On the grid provided on the next page, plot a graph of temperature against time for A and B. Draw a best-fit smooth curve for each set of readings.

3 © UCLES 2015 0654/53/O/N/15 [Turn over 0 1 2 3 4 5 time / minutes temperature / °C 6 7 8 9 10 [3] (d) By referring to your results, suggest why forming a huddle may be beneficial to Emperor Penguins. [2] (e) (i) Suggest one source of inaccuracy in this experiment. [1] (ii) Suggest how this experiment could be changed to reduce this source of inaccuracy. [1] (f) Describe and explain how the results from this experiment could be made more reliable. [1]

4 © UCLES 2015 0654/53/O/N/15 2 You are going to investigate the effect of solution X on the exothermic reaction between zinc and copper sulfate solution. You will carry out three different experiments. All temperatures should be recorded to the nearest 0.5 °C. (a) Experiment 1 • Measure to the nearest 0.5 °C the initial temperature T1 of the copper sulphate solution. Record in the correct box in Table 2.1 this temperature for experiment 1. • Place one of the portions of zinc in the plastic cup. • Using the measuring cylinder add 10 cm3 of copper sulfate solution to the zinc in the plastic cup. • Stir the mixture in the plastic cup continuously and measure to the nearest 0.5 °C the highest temperature T2 of the mixture. Record, in the correct box in Table 2.1, this temperature for experiment 1. • Look at the mixture and record your observations. observations [4] • Discard the mixture into the waste container provided and thoroughly wash out the plastic cup and the measuring cylinder with water. Table 2.1 experiment T1 / °C T2 / °C ΔT / °C volume of solution X used / cm3 1 0 2 5 3 10

5 © UCLES 2015 0654/53/O/N/15 [Turn over (b) Experiment 2 In this experiment solution X and copper sulfate are mixed and filtered before being added to the zinc. (i) • Using the measuring cylinder place 10 cm3 of copper sulfate solution in a small beaker. • Using the other measuring cylinder add 5 cm3 of solution X to the same beaker. • Stir the mixture in the beaker a few times. You will use this mixture in (b)(ii). • Look at the mixture and record your observations. observations [1] (ii) • Filter the mixture from (b)(i) into a large test-tube. • Measure the initial temperature T1 of the filtrate. Record in Table 2.1 T1 for experiment 2. • Place one of the portions of zinc in the plastic cup. • Using a clean measuring cylinder add 10 cm3 of the filtrate to the zinc in the plastic cup. • Stir the mixture in the plastic cup continuously and measure the highest temperature T2 of the mixture. Record, in Table 2.1, T2 for experiment 2. • Discard the mixture into the waste container provided and thoroughly wash out the plastic cup, the beaker and the measuring cylinders with water. [1] (c) Experiment 3 • Repeat (b) using 10 cm3 of solution X instead of 5 cm3 in part (i). • Remember to react only 10 cm3 of the filtrate with the zinc. • Record in Table 2.1 T1 and T2 for experiment 3. [2]

6 © UCLES 2015 0654/53/O/N/15 (d) (i) Calculate the change in temperature ΔT for each experiment. Record these values in Table 2.1. [2] (ii) State how ΔT varies with the amount of solution X used. [1] (iii) Using your observation in (b)(i), suggest an identity for solution X. solution X is [1] (iv) Using your results in Table 2.1 and your conclusion in (d)(iii), suggest an explanation for the relationship stated in (d)(ii). [2] (e) 10 cm3 of filtrate was added to the zinc in experiments 2 and 3 rather than all of the filtrate from the mixture of solution X and copper sulfate solution. Suggest a reason for this. [1]

7 © UCLES 2015 0654/53/O/N/15 [Turn over 3 You are going to investigate how the height of the shadow cast by an object on a screen changes as the distance from the object to the screen is varied. The lamp and screen have been set up for you as shown in Fig. 3.1. d H D screen object lamp Fig. 3.1 Place the screen at a distance D of 60 cm from the centre of the lamp. Distance D must not change during the experiment. (a) (i) Measure and record the height H of the object to the nearest 0.1 cm. H = cm [2] (ii) Place the object at a distance d of 55 cm from the centre of the lamp. The object will produce a shadow on the screen. Measure and record, in Table 3.1 on page 8, the maximum height h of the shadow to the nearest 0.1 cm. See Fig. 3.2. [1] screen shadow h Fig. 3.2

8 © UCLES 2015 0654/53/O/N/15 (iii) Repeat (a)(ii) for values of d of 50 cm, 45 cm, 40 cm and 35 cm. [3] (iv) State one difficulty you encountered when measuring the height of the shadow. [1] Table 3.1 d / cm h / cm 55 50 45 40 35 (b) On the grid provided on page 9, plot a graph of h (vertical axis) against d (horizontal axis). Label the axes. Draw the best-fit curve. [3] (c) (i) Use your graph to predict the height h of the shadow for a value of d = 30 cm. When d = 30 cm, h = cm [1] (ii) The height H of the object may be calculated using the value of h you found in (c)(i) by the equation H = 2 h Determine the height of the object using this equation. Show your working. H = cm [2] (iii) Extend the curve on your graph to predict the height of the shadow when d = 10 cm. When d = 10 cm, h = cm [1] (d) A student suggests that the distance d between the lamp and the object should be no less than 15 cm. Look at your results and the observations you made whilst performing the experiment and give one reason why this is a sensible suggestion. reason [1]

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12 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. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series. 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 2015 0654/53/O/N/15 NOTES FOR USE IN QUALITATIVE ANALYSIS Test for anions anion test test result carbonate (CO3 2-) add dilute acid effervescence, carbon dioxide produced chloride (Cl -) [in solution] acidify with dilute nitric acid, then add aqueous silver nitrate white ppt. nitrate (NO3 -) [in solution] add aqueous sodium hydroxide then aluminium foil; warm carefully ammonia produced sulfate (SO4 2-) [in solution] acidify then add aqueous barium chloride or aqueous barium nitrate white ppt. Test for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia ammonium (NH4 +) ammonia produced on warming - copper(II) (Cu2+) light blue ppt., insoluble in excess light blue ppt., soluble in excess giving a dark blue solution iron(II) (Fe2+) green ppt., insoluble in excess green ppt., insoluble in excess iron(III) (Fe3+) red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc (Zn2+) white ppt., soluble in excess giving a colourless solution white ppt., soluble in excess giving a colourless solution Test for gases gas test and test results ammonia (NH3) turns damp red litmus paper blue carbon dioxide (CO2) turns limewater milky chlorine (Cl2) bleaches damp litmus paper hydrogen (H2) “pops” with a lighted splint oxygen (O2) relights a glowing splint

® 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 2015 series 0654 CO-ORDINATED SCIENCES 0654/53 Paper 5 (Practical), maximum raw mark 45 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 2015 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 2015 0654 53 © Cambridge International Examinations 2015 1 (a) (first column heading is) time (in) minutes ; (subsequent column headings are) beaker A temperature °C and beaker B temperature °C, can be in any order ; [2] (b) two temperature recorded for time = 0 to 0.5 °C ; time = 0 readings within 5 °C of each other ; full set of results for beaker A and beaker B ; both sets decrease in temperature ; temperature at time = 10 is lower in beaker B ; [5] (c) linear scale for temperature axis such that plotting uses half of grid ; at least 5 points plotted correctly for either A or B ; two smooth best-fit curves ; [3] (d) test-tubes A cooled more slowly / retained heat / ORA ; prevents penguins getting too cold / helps body temperature to be maintained / less heat loss / less surface area exposed / ORA ; [2] (e) (i) different start temperatures / can’t read both thermometers at the same time / stirring water to ensure same temperature throughout / different thickness of test-tube / temperature recorded from only one of three in A ; [max 1] (any reasonable inaccuracy) (ii) do each set separately / record temperature of all three test-tubes in A ; [1] (f) repeat the experiment AND some explanation ; [1] [Total: 15] 2 (a) T1 recorded in correct box for experiment 1 ; T2 recorded in correct box for experiment 1 ; solution less blue / grey / colourless ; solid brown / darker grey / black ; [4] (b) (i) blue ppt. ; [1] (ii) T1 and T2 recorded in correct boxes for experiment 2 AND T2 lower than value in experiment 1 ; [1] (c) T1 and T2 recorded in correct box for experiment 3 AND T2 lower than value in experiment 2 ; all temperatures in table recorded to same accuracy ; [2]

Page 3 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2015 0654 53 © Cambridge International Examinations 2015 (d) (i) ∆T values correct ; ∆T values decrease down the table ; [2] (second mark may be awarded if ∆T values have not been entered in Table 2.1) (ii) ∆T decreases with increasing volume of solution X ; [1] (iii) sodium hydroxide / NaOH / other reasonable hydroxide ; [1] (not ammonia solution) (iv) X reacts with copper sulfate solution ; less copper sulfate to react with zinc and produce heat ; [2] (e) to keep the volume of liquid constant / for fair comparison of ∆T / because a larger volume would reduce the temperature ; [1] [Total: 15] 3 (a) (i) H recorded to nearest 0.1 cm ; H = 1.5 ± 0.1 cm ; [2] (ii) for d = 55 cm, value of h recorded ; [1] (iii) all values of h recorded ; values of h increasing ; when d = 35 cm, h between 2.1 cm and 3.1 cm ; [3] (iv) edges of shadow not distinct / h varies ; [1] (b) axes labelled with units ; at least four plots correct to half a small square ; good best-fit curve judgement ; [3] (c) (i) value correctly read from candidate’s graph to half a small square ; [1] (ii) H calculation correct ; (ecf from (c)(i)) H = 1.5 ± 0.2 cm ; [2] (accuracy mark so corrected as necessary) (iii) correct value from sensible extrapolation to half a small square ; [1] (d) shadow would become too big to fit on the screen / shadow becomes more blurred / hard to see shadow ; [max 1] [Total: 15]