Cambridge IGCSE Science - Combined 0653 — 2007 Oct/Nov Paper 5 · Variant 1

This document consists of 8 printed pages. IB07 11_0653_05/2RP © UCLES 2007 [Turn over *1479844611* For Examiner's Use 1 2 3 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMBINED SCIENCE 0653/05 Paper 5 Practical Test October/November 2007 1 hour 30 minutes Candidates answer on the Question Paper. Additional Materials: As listed in 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 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 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. www.XtremePapers.com

2 © UCLES 2007 0653/05/O/N/07 For Examiner's Use 1 (a) The beaker labelled A contains raisins that have been immersed in a dilute sugar solution overnight. Beaker B contains unsoaked raisins. (i) Remove one raisin from each beaker. Place them on the white tile. Draw the raisins in the spaces below. raisin A raisin B [2] (ii) Compare the appearance of the raisins. Describe what happened to the shape and size of raisin A while it was in the solution. Suggest why this change has occurred. [2] (b) The kidneys of animals can regulate the level of water and salts in their bodies by excreting urine. Healthy urine does not contain protein or sugar, but it does contain chloride ions. The four solutions, D, E, F and G have been made in the laboratory so that they are chemically similar to urine samples from different people. The four samples are • urine containing reducing sugar, from a diabetic patient, • urine containing protein, from a patient with kidney failure, • urine from a healthy person, • a sample that is not genuine urine (fake sample).

3 © UCLES 2007 0653/05/O/N/07 [Turn over For Examiner's Use You are going to identify the samples. For each test use 2 cm depth of sample in a test- tube. (i) Test each solution with Benedict's reagent. Record the colour of each sample after testing, in Fig. 1.1. (ii) Test each solution with biuret reagent. Record the colour of each sample after testing in Fig. 1.1. test on urine sample D sample E sample F sample G Benedict's test protein test Fig. 1.1 [4] (iii) Use the results from Fig. 1.1 to identify the sample from the patient with diabetes, kidney failure. [2]

4 © UCLES 2007 0653/05/O/N/07 For Examiner's Use 2 You are going to find out how the current through a piece of wire varies with its length. The circuit has been set up for you and is shown in Fig. 2.1. A fixed resistance A B 0 100 1 metre wire crocodile clip y Fig. 2.1 (a) S, the value of the resistance of one metre of the wire AB, has been given to you. State this value. S = ohms [1] (b) Using the crocodile clip, complete the circuit by touching the wire at the 10.0 cm (y = 10 cm) mark on the ruler. Read the current I and record this value in Fig. 2.2. (c) Repeat this measurement of current for the four further values of y shown in Fig. 2.2. Record your measurements in Fig. 2.2. length y / cm resistance R / ohms current I / amps current x resistance IR / volts 10.0 30.0 50.0 70.0 90.0 Fig. 2.2 [2] (d) (i) Calculate R the resistance of the wire for each length of y using the formula R = 100 y S × . S is the value recorded above in (a). Write these values in the appropriate column of the table. [1] (ii) Complete Fig. 2.2 by calculating IR, the potential drop, for each value of y, to three significant figures. [2]

5 © UCLES 2007 0653/05/O/N/07 [Turn over For Examiner's Use (e) Plot a graph of the potential drop, IR, against length y (horizontal axis). Both axes should start at zero. Draw a smooth curve through your points including the origin. [4]

6 © UCLES 2007 0653/05/O/N/07 For Examiner's Use 3 X, Y and Z are three colourless solutions. Carry out the following tests which will enable you to suggest a name for two of these solutions. Solution P is an indicator. It is colourless in acid solution and pink in alkaline solution. (a) Place about 1 cm3 of each solution X, Y and Z in separate test-tubes. Add two drops of solution P to each. Record your observations in the table. solution X solution Y solution Z [1] State your conclusion about each solution. solution X solution Y solution Z [2] (b) The acid is known to be either hydrochloric acid or sulphuric acid. Carry out the tests for a chloride and a sulphate as described on page 8 to decide the name of the acid. Describe the test and result that enables you to decide. Only one test need be described. name of acid [3] (c) (i) Place about 1 cm3 of solution Y in a test-tube. Add 1 drop of the indicator P. Add drops of solution X until there is no further change. Record your observations. observations [1] (ii) Repeat (c)(i) using solution Z in place of solution Y. Record your observations. observations [2]

7 © UCLES 2007 0653/05/O/N/07 For Examiner's Use (d) Suggest a name for solution Z. [1]

8 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 2007 0653/05/O/N/07 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 sulphate (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 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 October/November 2007 question paper 0653 COMBINED SCIENCE 0653/05 Paper 5 (Practical Test), maximum raw mark 30 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. All Examiners are instructed that alternative correct answers and unexpected approaches in candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills demonstrated. 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 October/November 2007 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 Syllabus Paper IGCSE – October/November 2007 0653 05 © UCLES 2007 1 (a) (i) clear drawings; ONE with visible differences between raisins (raisin A should be larger in size and rounder than raisin B); ONE [2] (ii) raisin A has become larger/rounder; ONE water has entered the raisin; ONE [2] (b) (i) first row of table below completed correctly; –1 for each incorrect to zero [2] (ii) second row of table below completed correctly; –1 for each incorrect to zero [2] test on urine sample D sample E sample F sample G Benedicts test blue blue red blue protein test blue blue blue lilac Allow orange for red. Allow purple or violet for G protein test (iii) (diabetes) sample F; (kidney failure) sample G; [2] [Total: 10] 2 (a) stating the value of resistance/m should be the same as supervisor and also candidates should have the same value as each other [1] (b) & (c) 5 values of y and I [2] (d) (i) R is correctly calculated current decreases with increasing x (but I should be less than 1) [1] (ii) IR is calculated correctly 2 dp used [2] (e) Graph S sensible scale used and axes labelled P plotting correct (allow one error) C smooth curve drawn Origin included [4] [Total: 10]

Page 3 Mark Scheme Syllabus Paper IGCSE – October/November 2007 0653 05 © UCLES 2007 3 (a) X is colourless/cloudy/stayed the same Y is pink Z is pink [1] all three need to be correct to score the mark X is an acid Y is an alkali Z is an alkali [2] each incorrect –1 to zero (b) test correctly described TWO marks acidifying not necessary acid is hydrochloric ONE [3] test can be for sulphate showing negative therefore must be chloride there must be evidence that the candidate actually performed the test (c) (i) pink colour disappears/colourless but not clear [1] (ii) pink colour disappears/colourless but not clear effervescence [2] (d) Z could be sodium carbonate [1] [Total: 10]