Cambridge IGCSE Science - Combined 0653 — 2016 May/June Paper 5 · Variant 1

This document consists of 8 printed pages. DC (ST/SW) 120981/3 © UCLES 2016 [Turn over * 3 2 5 9 4 8 8 3 2 9 * COMBINED SCIENCE 0653/51 Paper 5 Practical Test May/June 2016 1 hour 30 minutes 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 8. 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. Cambridge International Examinations Cambridge International General Certificate of Secondary Education For Examiner’s Use 1 2 3 Total

2 0653/51/M/J/16 © UCLES 2016 1 You are going to investigate the effectiveness of an enzyme in the extraction of apple juice from fruit. You are provided with two beakers, each containing 50 g of apple pulp and a third beaker containing an enzyme solution. The beakers are at a temperature of 35 °C in a water-bath. • Remove the beakers containing apple pulp from the water-bath. Label the beakers A and B. • Using the syringes add 2 cm3 of distilled water to beaker A and 2 cm3 of enzyme solution to beaker B. • Using the stirring rod provided, mix the contents of beaker A. Rinse and dry the stirring rod. Then mix the contents of beaker B using the stirring rod. • Return beakers A and B to the water-bath and immediately start the stopclock. • You now need to wait at least five minutes. During this time read the rest of the question and complete part (a). • Label the two measuring cylinders A and B. • Place a filter funnel in the top of each measuring cylinder. • Fold the two filter papers and place one in each filter funnel. (a) Insert headings, including units, in Table 1.1. [2] Table 1.1 … / … … / … cylinder A cylinder B 2 4 6 8 10 (b) After at least five minutes have elapsed on the stopclock, stop and reset the stopclock. Empty the contents of beaker A into the filter funnel in cylinder A and empty the contents of beaker B into the filter funnel in cylinder B. Start the stopclock. Clean the stirring rod and use it to help remove apple from the beakers if necessary. Record in Table 1.1 the volume of the juice collected in each measuring cylinder every 2 minutes for 10 minutes. [3]

3 0653/51/M/J/16 © UCLES 2016 [Turn over (c) On the grid provided, plot a graph of your results from beaker B only (vertical axis) against the values in column 1 of Table 1.1. Draw the best-fit line. [4] (d) Enzymes are used for juice extraction in the fruit juice industry. Use your results to suggest an advantage to manufacturers in using this enzyme for the production of fruit juice. …[1]

4 0653/51/M/J/16 © UCLES 2016 2 You are provided with three solutions C, D and E of acid X. Their concentrations are: 0.50 mol / dm3 (least concentrated) 1.00 mol / dm3 2.00 mol / dm3 (most concentrated). It is not known which is which. (a) (i) You are going to carry out an investigation to find out the concentration of each solution. • Using a measuring cylinder place 5 cm3 of solution C in a test-tube. • Add a 1 cm piece of magnesium ribbon to this test-tube and start the stopclock. • Use the stirring rod to keep the magnesium ribbon in the acid. • When the magnesium ribbon has completely reacted and disappeared stop the stopclock and record in Table 2.1 the time in seconds. • If the magnesium ribbon is still present after 3 minutes, record the time as >180 s. • Repeat the above procedure for solutions D and E. [4] Table 2.1 solution of acid X time / s C D E (ii) Use your results in Table 2.1 to conclude which solution of X has which concentration. C has a concentration of … mol / dm3 D has a concentration of … mol / dm3 E has a concentration of … mol / dm3 [2]

5 0653/51/M/J/16 © UCLES 2016 [Turn over (b) Plan, in detail, another experiment to find out which acid solution has which concentration. The experiment must be different from the one in (a). You will NOT be carrying out your plan. You may use any of the chemicals in the following list but you do not have to use all of them. Choose a chemical or chemicals which you know will react with acids: barium chloride solution limewater magnesium ribbon marble chips silver nitrate solution sodium hydroxide solution Universal Indicator State clearly: • what you will do to carry out a fair test • what apparatus you will use • what observations and measurements you will make • how you will use your observations and measurements to make conclusions. … … … … … … … …[4]

6 0653/51/M/J/16 © UCLES 2016 3 You are going to measure the mass of a metre rule using a balancing method. You are provided with a 100 g load labelled L, a metre rule and a pivot. L 0.0 cm 100.0 cm 50.0 cm mark d x y p Fig. 3.1 (a) (i) • Set up the apparatus as shown in Fig. 3.1. • Place the load L on the rule so that its centre is at a distance d = 5.0 cm from the zero end of the rule. • Adjust the position of the pivot so that the rule balances on it. • Record, to the nearest 0.1 cm, in Table 3.1, the distance p from the pivot to the zero end of the rule. [1] (ii) Repeat the procedure in (a) (i) for values of d of 10.0 cm, 15.0 cm and 20.0 cm. [1] (b) For each value of d, calculate the distances x and y as shown in Table 3.1. Use the equations shown. x = (p – d) y = (50 – p) Record in Table 3.1 your calculated values of x and y. [2] Table 3.1 d / cm p / cm x = (p – d) / cm y = (50 – p) / cm 5.0 10.0 15.0 20.0

7 0653/51/M/J/16 © UCLES 2016 (c) (i) On the grid provided, plot a graph of y (vertical axis) against x. You do not need to start your axes from the origin (0, 0). Draw the best-fit straight line. [3] y / cm x / cm (ii) Calculate the gradient of your line. Show all working and indicate on your graph the values you chose to enable the gradient to be calculated. gradient of line = …[2] (d) The mass in grams of the metre rule is given by the equation shown. mass = 100 gradient Use this equation to calculate the mass of the rule, giving your answer to an appropriate number of significant figures. mass of rule = … g [1]

8 0653/51/M/J/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. 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. This document consists of 3 printed pages. © UCLES 2016 [Turn over Cambridge International Examinations Cambridge International General Certificate of Secondary Education COMBINED SCIENCE 0653/51 Paper 5 Practical Test May/June 2016 MARK SCHEME Maximum Mark: 30 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 May/June 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 – May/June 2016 0653 51 © Cambridge International Examinations 2016 1 (a) time (in) minutes ; [2] volume (in) cm3 (ALLOW ml); time with no units and volume with no units = 1 mark (b) full set of results for A ; (ALLOW zeros if SV has zeros) [3] full set of results for B ; (ALLOW zeros if SV has zeros) more juice produced in B for at least 4 readings; (c) axes labelled with units (ecf from (a) but IGNORE ecf if correct) ; [4] suitable linear scale using at least half the grid ; at least 4 plots correct ± half small square ; best-fit line ; (IGNORE extrapolation to zero) IF plot A and B IGNORE A IF plot A only then cannot score MP3 but can score but can score M1, M2 and M4 IF all points are zeros then can only score M1 (d) increases amount of juice produced per unit time / more juice / speeds extraction process ; [1] 2 (a) (i) reading for C (not zero) ; [4] readings for D and E (not zero) ; all readings in s ; D>E>C ; (ii) C is 2.00 mol dm–3 [2] D is 0.50 mol dm–3 E is 1.00 mol dm–3 one correct ; all three correct ; (b) apparatus [4] stopwatch AND one of: test-tube, measuring cylinder, delivery tube as appropriate / apparatus for measuring volume of acid AND apparatus for adding drops of alkali ; fair test add same amounts or size of Mg / marble chip / UI (to acid solutions) / same volume of acid (if doing neutralisation) same temperature ; measurement count bubbles (in a certain time) / time for marble chip to disappear / time for limewater to go milky / volume of gas (in a certain time) / volume of NaOH to change UI ;

Page 3 Mark Scheme Syllabus Paper Cambridge IGCSE – May/June 2016 0653 51 © Cambridge International Examinations 2016 conclusion more bubbles is more concentrated / more volume of gas is more concentrated / shorter time is more concentrated / greater volume of NaOH is more concentrated ; 3 (a) (i) p value for d = 5.0 recorded ; [1] ALLOW p>50 (ii) values of p increasing ; [1] (b) all recorded x values correct ; [2] all recorded y values correct ; (c) (i) suitable choice of scales (⩾ ½ the grid used) ; [3] at least 3 points plotted correctly to ½ small square (penalise ‘blobs’) ; good best-fit straight line judgement ; IF plot d can only get M3 (ii) indication on graph of how data were obtained AND more than half the line used ; [2] calculation correct ; DO NOT ALLOW either marks if gradient taken over non-linear scale part of line IGNORE missing minus if negative gradient (d) m present to 2 / 3 significant figures and correct rounding ; [1]