Cambridge IGCSE Physical Science 0652 — 2016 Oct/Nov Paper 6 · Variant 2

This document consists of 21 printed pages and 3 blank pages. DC (RW/SG) 128601/2 © UCLES 2016 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education * 9 4 9 6 8 5 8 2 0 4 * PHYSICAL SCIENCE 0652/62 Paper 6 Alternative to Practical October/November 2016 1 hour 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 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. 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 0652/62/O/N/16 © UCLES 2016 1 A science teacher gives a student a sample of limestone. She wants the student to find the percentage of calcium carbonate in the sample. The student decides to carry out the experiment in four parts as follows: 1. find the mass of the sample of limestone, 2. add hydrochloric acid to react with the calcium carbonate, 3. measure the volume of the carbon dioxide given off, 4. filter off the residue and find its mass. (a) Part 1 Finding the mass of the sample of limestone Fig. 1.1 shows the balance reading for the mass of the sample of limestone. Read the scale and record the mass to the nearest 0.05 g. 1.50 1.00 0.50 g Fig. 1.1 mass of limestone = … g [1] (b) Part 2 Reacting the hydrochloric acid with the calcium carbonate The student uses the apparatus shown in Fig. 1.2 to react the limestone with excess hydrochloric acid and collect the gas given off. carbon dioxide measuring cylinder water limestone and excess hydrochloric acid Fig. 1.2 State a reason why carbon dioxide gas can be collected over water in this way. … …[1]

3 0652/62/O/N/16 © UCLES 2016 [Turn over (c) Part 3 Measuring the volume of carbon dioxide (i) Fig. 1.3 shows the measuring cylinder from Fig. 1.2 at the end of the reaction. Read the scale and record the volume of carbon dioxide to the nearest 5 cm3. 100 200 300 cm3 carbon dioxide Fig. 1.3 volume of carbon dioxide = … cm3 [1] (ii) The teacher gives the student a formula to find the mass of calcium carbonate that produced this volume of carbon dioxide. mass of calcium carbonate (g) = volume of carbon dioxide 240 (cm3) Use the formula and your answer from (c)(i) to find the mass of calcium carbonate in the original sample of limestone. mass of calcium carbonate = … g [1]

4 0652/62/O/N/16 © UCLES 2016 (d) Part 4 Filtering off and finding the mass of the residue The student finds the mass of a filter paper. She filters the mixture from part 2. (i) Complete Fig. 1.4 to show how she filters the mixture. Include labels in your drawing. flask containing mixture filtrate Fig. 1.4 [1] (ii) The student dries the filter paper and residue and finds their mass. Complete the calculation to find the mass of the residue. 0.75 mass of residue + filter paper = … g 0.59 mass of filter paper = … g mass of residue = … g [1] (iii) Use the answers to (a) and (d)(ii) to calculate the actual mass of calcium carbonate in the original sample of limestone. mass of calcium carbonate = … g [1]

5 0652/62/O/N/16 © UCLES 2016 [Turn over (e) (i) Calculate the percentage of calcium carbonate in the sample of limestone (purity) using the formula below and the answers to (a) and (c)(ii). percentage = mass of calcium carbonate mass of limestone × 100 percentage of calcium carbonate = … % [1] (ii) Calculate the percentage of calcium carbonate in the sample of limestone (purity) using the answers to (a) and (d)(iii). percentage of calcium carbonate = … % [1] (f) One of the impurities in the limestone is magnesium carbonate. This makes the calculated percentage of calcium carbonate too high. Explain this statement. … …[1]

6 0652/62/O/N/16 © UCLES 2016 2 A student investigates the reaction between magnesium and copper sulfate solution. She wants to find out how the reaction depends on the concentration of the copper sulfate solution. She is provided with copper sulfate solution of concentration 1.00 X, where X is a unit of concentration. (a) The student uses a thermometer to measure the initial temperature Ti of the copper sulfate solution. She records in Table 2.1 Ti to the nearest half degree for concentration 1.00 X. Table 2.1 concentration of copper sulfate / X initial temperature Ti / ° C highest temperature Th / ° C temperature change ∆T / ° C 1.00 22.0 76.0 0.75 22.0 63.5 0.50 22.0 52.0 0.25 • The student transfers a sample of magnesium powder into a plastic cup. • She measures 24 cm3 of copper sulfate solution and adds this quickly to the magnesium in the plastic cup. • She stirs the mixture thoroughly and measures the highest temperature Th reached. • She records in Table 2.1 Th to the nearest half degree for concentration 1.00 X. • She observes that the solid in the mixture turns brown. (i) State the identity of the brown solid. solid …[1] She then repeats the experiment using copper sulfate solutions of different concentrations, 0.75 X, 0.50 X, 0.25 X. She records in Table 2.1 the values of Ti and Th to the nearest half degree for concentrations 0.75 X and 0.50 X. (ii) Read the thermometers in Fig. 2.1 and record to the nearest half degree in Table 2.1 the values of Ti and Th for magnesium and 0.25 X copper sulfate solution. [2] 35 30 25 15 20 45 40 35 25 30 thermometers for 0.25 X Th Ti Fig 2.1

7 0652/62/O/N/16 © UCLES 2016 [Turn over (b) (i) Calculate the temperature change ∆T during the reaction for each concentration of copper sulfate solution. Record these values in the last column of Table 2.1. [1] (ii) Plot a graph of temperature change ∆T against concentration of copper sulfate solution on the grid provided. Draw the best-fit straight line through the origin. [3] temperature change ∆T / °C concentration of copper sulfate / X 0 0 0.20 0.40 0.60 0.80 1.00 0.10 0.30 0.50 0.70 0.90

8 0652/62/O/N/16 © UCLES 2016 (iii) A student states that the temperature change ∆T for this experiment is directly proportional to the concentration of the copper sulfate solution used. Suggest whether this statement is supported by the data and justify your answer. … … …[1] (c) (i) Using the data in Table 2.1, state the name of this type of chemical reaction. …[1] (ii) Suggest one change to this procedure to improve the accuracy of the results. … …[1]

9 0652/62/O/N/16 © UCLES 2016 [Turn over Please turn over for Question 3.

10 0652/62/O/N/16 © UCLES 2016 3 A student finds the mass of a piece of modelling clay using a balancing method. She moulds the piece of modelling clay until it is roughly cube-shaped. She places the modelling clay on a metre rule so that its centre is 15.0 cm from the zero end of the rule, as shown in Fig. 3.1. 0.0 cm 50.0 cm 100.0 cm 15.0 cm a b modelling clay pivot metre rule bench Fig. 3.1 (not to scale) (a) Describe how the student ensures that the centre of the modelling clay is directly above the 15.0 cm mark on the rule. You may draw a diagram to help your answer. … … …[1]

11 0652/62/O/N/16 © UCLES 2016 [Turn over (b) The student adjusts the position of the pivot so that the rule balances on it as shown in Fig. 3.2 (seen from above). 15.0 cm 0 modelling clay pivot a b 10 20 30 40 50 60 70 80 90 100 rule 37 36 Fig. 3.2 (i) Record the position of the pivot on the rule to the nearest 0.1 cm. position of pivot = … cm [1] (ii) Calculate the distance a. a = … cm [1] (iii) Calculate the distance b. b = … cm [1]

12 0652/62/O/N/16 © UCLES 2016 (c) The student then uses a balance to measure the mass M of the metre rule. Fig. 3.3 shows the reading on the balance. g Fig. 3.3 (i) Write down the mass M of the metre rule to the nearest 0.1 g. M = … g [1] (ii) She uses the equation, shown below, to calculate the mass m of the modelling clay. m = M × b a Calculate the mass of the modelling clay, giving your answer to an appropriate number of significant figures. m = … g [2] (d) Even if the student carried out the experiment very carefully, her value for the mass of the modelling clay will only be approximate. Suggest two reasons, based upon the practical method used, why this might be so. Assume that the balance used to find the mass of the rule is accurate. 1 … … 2 … … [2] (e) The experiment is repeated with a heavier piece of modelling clay. State how the distances a and b will change. … …[1]

13 0652/62/O/N/16 © UCLES 2016 [Turn over 4 The science class compares the passage of light rays through water and through glass. Fig. 4.1 shows some of the apparatus that they use. light ray paper P Fig. 4.1 First, the students shine a light ray towards the paper at an angle of 45°. They mark the position where the light ray hits the paper with a P, as shown in Fig. 4.1. Then they place a container of water in the path of the light ray. They mark the new position where the light ray hits the paper with a PW, as shown in Fig. 4.2. light ray container of water paper PW P Fig. 4.2 (a) (i) Describe how the students use a lamp to produce a narrow light ray. … … … …[1]

14 0652/62/O/N/16 © UCLES 2016 (ii) Fig. 4.3 shows a side view of the light ray, container of water and paper. Complete the diagram in Fig. 4.3 to show the path of the light ray as it passes through the water to hit the paper at position PW. [2] 45° PW P container water path of light ray without container of water normal light ray paper Fig. 4.3 (iii) Use a ruler to measure to the nearest 0.1 cm the distance between P and PW in Fig. 4.3. distance = … cm [1] (iv) On Fig. 4.3, label with an I the angle of incidence and an R the angle of refraction where the ray of light meets the water. [1]

15 0652/62/O/N/16 © UCLES 2016 [Turn over The students replace the water with a glass block of the same thickness and repeat the experiment. The light ray now hits the paper at position PG as shown in Fig. 4.4. 45° PG P glass block path of light ray without glass block normal light ray paper Fig. 4.4 (v) Use a ruler to measure to the nearest 0.1 cm the distance between P and PG in Fig. 4.4. distance = … cm [1] (vi) Compare your answers to (a)(iii) and (a)(v). Explain why PW and PG are different distances from point P. … … …[1]

16 0652/62/O/N/16 © UCLES 2016 (b) Using the glass block, the students now change the angle between the light ray and the normal to 70°. The point where the light ray hits the paper is dimmer with the glass block than without the glass block. This is because some of the light ray is reflected at the upper surface of the glass block. (i) Complete Fig. 4.5 to show this reflection and mark the angle of reflection with an r. [2] glass block light ray Fig. 4.5 (ii) State the expected value of the angle of reflection. angle = … ° [1]

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18 0652/62/O/N/16 © UCLES 2016 5 The teacher gives a student five unlabelled bottles. The bottles contain dilute solutions of the following. hydrochloric acid nitric acid sulfuric acid ammonia sodium hydroxide (a) Identifying the solutions The student must identify each solution. He carries out the following tests. (i) The student correctly identifies one of the solutions by its smell. Name the solution. …[1] (ii) The student adds barium nitrate solution to 1 cm3 of each of the solutions and correctly identifies the bottle containing sulfuric acid. State the observation that enables him to identify the sulfuric acid. … …[1] (iii) The student uses a chemical test to identify the hydrochloric acid. Suggest the test that he uses and the observation that he makes. test … observation … … [2] (iv) The student puts 1 cm3 of copper(II) sulfate into a test-tube. He then adds one of the remaining solutions drop by drop until it is in excess. State the observation that proves that this solution is sodium hydroxide. … …[1]

19 0652/62/O/N/16 © UCLES 2016 [Turn over (b) Making a salt The teacher asks the student to prepare a solid sample of the salt, sodium chloride, from the hydrochloric acid and sodium hydroxide solutions. • The student measures out 25 cm3 of hydrochloric acid and adds two drops of an indicator. • He adds sodium hydroxide solution until the mixture is neutral. • He records the volume of sodium hydroxide solution used as 18 cm3. • He washes out the glassware. • He now adds 18 cm3 sodium hydroxide solution to 25 cm3 hydrochloric acid without any indicator. • From this mixture the student obtains a solid sample of sodium chloride. (i) Name a piece of apparatus that the student can use to accurately measure 25 cm3 of hydrochloric acid. …[1] (ii) Suggest the name of an indicator that he can use and the colour change that takes place when the acid is neutralised. name of indicator … colour change, from … to … [2] (iii) Explain why the student repeated the reaction without the indicator. … …[1] (iv) State how the student obtains the sample of solid sodium chloride from the reaction mixture. … …[1]

20 0652/62/O/N/16 © UCLES 2016 6 A student is comparing the conduction of heat through two different materials. He has two containers labelled F and G. The containers are made from different materials. • The student places 200 cm3 of water at about 85 °C in container F. • He allows the contents of container F to cool to 80 °C. • He places 400 cm3 of water at exactly 20 °C in a large beaker. • When the temperature of the water in container F is 80 °C, he puts the container into the large beaker as shown in Fig. 6.1. thermometer stirrer large beaker 400 cm3 water at 20 °C 200 cm3 water at 80 °C container F Fig. 6.1 • He immediately starts a stopclock. • Every 30 seconds he measures and records the temperature of the water in container F. • He repeats this procedure using container G. • Some of his results are shown in Table 6.1. Table 6.1 time / s 0 30 60 90 120 150 180 temperature in F / °C 80 71 59 54 51 49 temperature in G / °C 80 64 55 45 42 40 (a) Fig. 6.2 shows the thermometer readings for the temperatures missing from Table 6.1. Read the thermometer scales to the nearest 1°C and record these readings in Table 6.1. [2] 50 40 70 60 °C °C G F Fig. 6.2

21 0652/62/O/N/16 © UCLES 2016 [Turn over (b) Plot graphs of the temperatures (vertical axis) in containers F and G against time (horizontal axis) on the grid provided. The temperature axis does not need to start at zero. Draw a best-fit curve for each container. [4]

22 0652/62/O/N/16 © UCLES 2016 (c) (i) State which container, F or G, is made of a material that is the better conductor of heat. Explain your answer. container ……… reason … … [1] (ii) Use your knowledge of the conduction of heat to suggest possible materials from which containers F and G are made. container F … container G … [2] (d) Immediately after the final temperature reading in container G, the student measures the temperature of the water in the large beaker. Suggest a value for this temperature. … ° C [1]

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24 0652/62/O/N/16 © UCLES 2016 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. BLANK PAGE

® IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 6 printed pages. © UCLES 2016 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education PHYSICAL SCIENCE 0652/62 Paper 6 Alternative to Practical October/November 2016 MARK SCHEME Maximum Mark: 60 Published 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 2016 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 2016 0652 62 © UCLES 2016 Question Answers Marks 1(a) 1.10 g ; 1 1(b) Only very slightly soluble inwater / insoluble (in water) ; 1 1(c)(i) 225 ; 1 1(c)(ii) 0.9375 / 0.94 (accept 0.9) ; 1 1(d)(i) filter funnel and filter paper shown and labelled ; 1 1(d)(ii) 0.16 ; 1 1(d)(iiii) (1.10 – 0.16) = 0.94 ; 1 1(e)(i) 0.9375 / 1.10 × 100 = 85 / 85.2 (%) ; ecf from (a) and (c)(ii) 1 1(e)(ii) 0.94 / 1.10 × 100 = 85 / 85.5 (%) ; ecf from (a) and (d)(iii) 1 1(f) (Magnesium carbonate) reacts like calcium carbonate / also gives carbon dioxide / results in too much carbon dioxide / is not in the residue ; 1 Total: 10 Question Answers Marks 2(a)(i) copper / Cu ; 1 2(a)(ii) 23.0 ; 38.5 ; 2

Page 3 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0652 62 © UCLES 2016 Question Answers Marks 2(b)(i) 54(.0), 41.5, 30(.0), 15.5 ; ecf 1 2(b)(ii) vertical scale linear and uses more than half of grid ; minimum of 3 points plotted correctly to within half a small square ; best straight line through origin ; 3 2(b)(iii) agrees as all points close to / on straight line (through origin) ; 1 2(c)(i) exothermic ; 1 2(c)(ii) lid / insulation around cup / more accurate thermometer / repeat with different concentrations (extra points) ; 1 Total: 10 Question Answers Marks 3(a) note the reading on either side and find mean / shown on a diagram / measure cube and mark the mid point ; 1 3(b)(i) 36 (.0 ) ; 1 3(b)(ii) 21 (.0) cm ; 1 3(b)(iii) 14 (.0) cm ; 1 3(c)(i) 84.4 g ; 1 3(c)(ii) 56 to 56.2666… ; 56 / 56.3 g (2 / 3 significant figures) ; 2

Page 4 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0652 62 © UCLES 2016 Question Answers Marks 3(d) any 2 centre of gravity of the rule not at the 50 cm mark ; difficulty in obtaining balance of ruler ; pivot not at right angles to edge of rule ; cube irregular ; ruler mass rounded ; max 2 3(e) a smaller and b greater ; 1 Total: 10 Question Answers Marks 4(a)(i) slit in a card (after lamp) ; 1 4(a)(ii) light ray bends towards the normal as it enters water solution and meets Pw ; incident and refracted rays are parallel ; 2 4(a)(ii) 1.1 cm (± 0.1 cm) ; 1 4(a)(ii) both angles of incidence and refraction correctly labelled ; 1 4(a)(ii) 2.0 cm (± 0.1 cm) ; 1 4(a)(ii) the angle of refraction is greater when the light ray passes through glass / glass bends light more than water ; 1 4(b)(i) reasonable accurate reflected ray drawn ; reflected angle marked between drawn normal and ray ; 2 4(b)(ii) 70° ; 1 Total: 10

Page 5 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0652 62 © UCLES 2016 Question Answers Marks 5(a)(i) ammonia / NH3 ; 1 5(a)(ii) white precipitate / white solid ; 1 5(a)(iii) add silver nitrate ; white precipitate ; 2 5(a)(iv) blue ppt. ; 1 5(b)(i) measuring cylinder / pipette / burette ; 1 5(b)(ii) UI ; red to green ; 2 5(b)(iii) salt would be impure / salt would be coloured ; 1 5(b)(iv) heat ; 1 Total: 10 Question Answers Marks 6(a) 64 (F) ; 49 (G) ; 2 6(b) axes labelled with units ; suitable scales chosen for axes using at least half of grid ; at least 4 points plotted ± ½ square for each container ; smooth curves drawn (and labelled) ; 4 6(c)(i) G is better (no mark) because the temperature fell more rapidly / lower curve ; 1

Page 6 Mark Scheme Syllabus Paper Cambridge IGCSE – October/November 2016 0652 62 © UCLES 2016 Question Answers Marks 6(c)(ii) named non-metallic material for F, e.g. polythene / wood / plastic ; named metallic material for G, e.g. copper / metal ; 2 6(d) value in region 21 to 40 °C ; 1 Total: 10