Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2010 May/June Paper 5 · Variant 2

This document consists of 12 printed pages. IB10 06_0654_52/5RP © UCLES 2010 [Turn over *6146709691* For Examiner's Use 1 2 3 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/52 Paper 5 Practical Test May/June 2010 2 hours Candidates answer on the Question Paper. Additional Materials: As listed in Instructions to Supervisors 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, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. Chemistry practical notes 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. www.XtremePapers.com

2 © UCLES 2010 0654/52/M/J/10 For Examiner's Use 1 This question is about variation in leaves. (a) You are provided with 20 leaves of the same species. Measure the length l of each leaf in millimetres as shown in Fig. 1.1a. If the lamina does not meet the petiole evenly on either side of the leaf use the longer measurement. See Fig. 1.1b. Enter your measurements in Table 1.1. l Fig. 1.1a l Fig. 1.1b lamina petiole Table 1.1 length of leaf l / mm 1 11 2 12 3 13 4 14 5 15 6 16 7 17 8 18 9 19 10 20 [2] (b) Calculate the average (mean) length of the 20 leaves. Show your working. average = mm [2]

3 © UCLES 2010 0654/52/M/J/10 [Turn over For Examiner's Use (c) (i) Enter the number of leaves in each range in Table 1.2 below. [2] Table 1.2 range / mm number of leaves in range range / mm number of leaves in range 30 - 34 90 - 94 35 - 39 95 - 99 40 - 44 100 - 104 45 - 49 105 - 109 50 - 54 110 - 114 55 - 59 115 - 119 60 - 64 120 - 124 65 - 69 125 - 129 70 - 74 130 - 139 75 - 79 140 - 144 80 - 84 145 - 149 85 - 89 150 - 154 (ii) Use the information you have entered in Table 1.2 to draw a bar chart on the grid provided. Use the number of leaves in range as the vertical axis and the range / mm as the horizontal axis. Choose suitable scales for your data. [3]

4 © UCLES 2010 0654/52/M/J/10 For Examiner's Use (d) The difference between the greatest length and the smallest length is the range. Complete the following. the greatest length = mm the smallest length = mm the range = mm [1] (e) Use the grid provided on page 5 to estimate the area of one of the leaves. The area of each square is 1 cm2. • Place the leaf on the grid provided. • Carefully draw round the leaf then remove it. • Write the letter C in the complete squares. Count the number of complete squares. number of complete (C) squares = • Write the letter P in any incomplete squares that have an area of half a square or more. number of incomplete (P) squares = • Ignore the rest of the squares. • Add C + P to estimate the area of the leaf. leaf area = cm2 [1]

5 © UCLES 2010 0654/52/M/J/10 [Turn over For Examiner's Use [2] (f) The leaves in the sample were all of the same species yet they showed variation in length. Suggest and explain a reason for this. reason explanation [2]

6 © UCLES 2010 0654/52/M/J/10 For Examiner's Use 2 You are going to find the specific heat capacity of the material of a can. The specific heat capacity of a material is the heat energy required to raise 1 g of the material by 1 ºC. (a) Find the mass of the can to the nearest gram. Record its mass below. mass of can, m1 = g [1] (b) Place the lagging around the can. Place the thermometer inside the can and leave for two minutes. Read the temperature, t1, to the nearest 0.5 ºC and record it below. temperature of can, t1 = ºC [1] (c) (i) Heat enough water in a beaker to about one-third fill the can. When the temperature is just above 70 ºC, remove the Bunsen. As soon as the temperature of the water has cooled to exactly 70.0 ºC pour the water into the can. Read the temperature, t2, to the nearest 0.5 ºC of the water after exactly two minutes. Record this temperature. temperature of water, t2 = ºC [1] (ii) Remove the lagging and pour the water into a measuring cylinder. Record the volume. volume of water = cm3 [1] (iii) 1 cm3 of water has a mass of 1 g. Calculate the mass, m2, of the volume of water you recorded in (c)(ii). mass of water, m2 = g [1] (d) Calculate (i) t3, the fall in temperature of the hot water, t3 = (70.0 - t2). t3 = ºC (ii) t4, the rise in temperature of the can, t4 = (t2 - t1). t4 = ºC [2]

7 © UCLES 2010 0654/52/M/J/10 [Turn over For Examiner's Use (e) (i) Use the equation to calculate the specific heat capacity, shc, of the material of the can. shc x m1 x t4 = m2 x t3 x 4.2 specific heat capacity of the material of the can = J g-1 ºC-1 [4] (ii) Use your answer from (e)(i) to calculate the specific heat capacity in J kg-1 ºC-1. specific heat capacity of the material of the can = J kg-1 ºC-1 [1] (f) The teacher said that the specific heat of a liquid, in joules per kilogram of the liquid per degree, can be found by placing an electrical heater in the liquid and measuring the temperature rise. What other measurements would be needed to calculate the specific heat capacity of the liquid? [3]

8 © UCLES 2010 0654/52/M/J/10 For Examiner's Use 3 You are going to investigate the rate of reaction between magnesium and hydrochloric acid. Read through the procedure before starting the experiment. (a) (i) Set up the apparatus as shown in Fig. 3.1. ● Fill the 100 cm3 measuring cylinder and trough with water. 100 cm3 measuring cylinder hydrochloric acid and magnesium water Fig. 3.1 (ii) ● Place 20 cm3 of the hydrochloric acid in the large test-tube. • Cut 6 cm of magnesium ribbon from the length provided. • Loosely fold the piece of magnesium ribbon and place it in the acid contained in the test-tube. Immediately replace the stopper and delivery tube and start the timer. • Read the volume of gas in the measuring cylinder after 20, 40, 60 and 80 seconds. • Record the volumes in Table 3.1. [2] (b) (i) You will now repeat the procedure using the same length of magnesium but different volumes of acid and water. • Wash out the contents of the test-tube. • Refill the measuring cylinder with water. • Place 16 cm3 of hydrochloric acid in the test-tube and 4 cm3 of water. • Cut 6 cm of magnesium ribbon and place it in the acid. Replace the stopper and delivery tube. • Immediately start the timer. • Read the volume of gas in the measuring cylinder after 20, 40, 60 and 80 seconds. • Record the volumes in Table 3.1.

9 © UCLES 2010 0654/52/M/J/10 [Turn over For Examiner's Use (ii) Repeat the experiment two more times using volumes of acid and water as shown in Table 3.1. Record the results in Table 3.1. [2] Table 3.1 volume of gas collected / cm3 after volume of 2 mol / dm3 hydrochloric acid / cm3 volume of water / cm3 concentration of acid in the mixture / mol / dm3 20 s 40 s 60 s 80 s 20 0 2.0 16 4 1.6 12 8 4 16 (c) Complete column 3 in Table 3.1. [1]

10 © UCLES 2010 0654/52/M/J/10 For Examiner's Use (d) Draw a graph of volume of gas collected after 40 s (vertical axes) against concentration of hydrochloric acid. Include the origin in your plots and draw a smooth curve. [4]

11 © UCLES 2010 0654/52/M/J/10 For Examiner's Use (e) How is the rate of reaction affected by concentration of acid? Explain how your results enable you to decide this. [2] (f) Had any of the reactions finished by the time 80 s had been reached? Explain your answer. [1] (g) The teacher said that if powdered magnesium is used in the experiment instead of a metal strip, the results will be different. Describe an experiment to find what would be different. Suggest what the difference might be. [3]

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. University of 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 2010 0654/52/M/J/10 CHEMISTRY PRACTICAL NOTES 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

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the May/June 2010 question paper for the guidance of teachers 0654 CO-ORDINATED SCIENCES 0654/52 Paper 52 (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 must be read in conjunction with the question papers and the report on the examination. • CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the May/June 2010 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Page 2 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0654 52 © UCLES 2010 1 (a) measurements entered correctly; and clearly in mm; [2] (b) correct method for calculating average; correct answer according to candidate’s data; [2] (c) (i) correct numbers of leaves in each range according to candidate’s own data entered clearly; [2] (ii) correct scales; correct plotting; correct drawing of bars (should be even width); [3] (d) range calculated correctly according to student’s data; [1] (e) correct number of complete squares; correct number of greater-than-half incomplete squares; correct calculation of area; [3] (f) any suitable factor + explanation e.g. variation in light intensity/carbon dioxide; gives different rates of photosynthesis; can also have different water/mineral availability [2] [Total: 15] 2 (a) mass of can to nearest gram; [1] (b) recorded to nearest 0.5 oC; [1] (c) (i) sensible temperature measured to 0.5 oC; [1] (ii) sensible volume of water; [1] (iii) mass of water correctly calculated; [1] (d) each correctly calculated;; [2]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2010 0654 52 © UCLES 2010 (e) (i) correct substitution; rearranging the equation; correct calculation; comparison with supervisor +/- 1 J; [4] (ii) correct conversion to J kg-1 oC-1; [1] (f) mass of liquid; power of heater; time heater is on; [3] [Total: 15] 3 (a) all readings for 5 experiments;; one mark if any space in the timing columns [2] (b) values across table increase; values down each column decrease; [2] (c) correct completion of third column in table; [1] (d) axes correct; sensible scale; plotting correct; suitable curve drawn; [4] (e) rate increases with concentration; more gas at any given time with the 2 M; [2] (f) gas still being released; [1] (g) repeat experiment using powder Mg, must use same mass of Mg; amount of gas at each time will be greater; greater surface area is the reason; [3] [Total: 15]