CIE Jun 2013 v1 Paper 3 Q3

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Examiners For Use Qualitative Analysis At each stage of any test you are to record details of the following.colour changes seen the formation of any precipitate the solubility of such precipitates in an excess of the reagent added Where gases are released they should be identi ed by a test, described in the appropriate place in your observations. You should indicate clearly at what stage in a test a change occurs. Marks are not given for chemical equations. No additional tests for ions present should be attempted. If any solution is warmed, a boiling tube MUST be used. Rinse and reuse test-tubes and boiling tubes where possible. Where reagents are selected for use in a test, the name or correct formula of the element or compound must be given. (a) FA 5, FA 6, FA 7 and FA 8 are aqueous solutions each of which contains a single cation and a single anion. Some of the ions present are listed below. Pb2+ ClCO3 2 CrO4 2 By observing the reactions that occur when pairs of the solutions are mixed together, you will be able to identify which solution contains which of these ions.UCLES 2013 9701/31/M/J/13 [Turn over<br /> 10 Use a 1 cm depth of each solution in a test-tube and record your observations in the following table. FA 6 FA 7 FA 8 Examiners For Use FA 5 FA 6 FA 7 (b) From your observations deduce which solution contains each of the following ions. ion solution Pb2+ ClCO3 2 CrO4 2 II III IV VI VII VIII II [8] [2] (c) Identify another ion that is present in one of the solutions. Explain your reasoning. ionexplanation[1]UCLES 2013 9701/31/M/J/13<br /> Examiners For Use 11 (d) (i) If chloride ions, Cl , were to be replaced with bromide ions, Br , in one of the solutions, would it make any difference to the observations you made in (a)? Explain your answer.(ii) FA 9 is an aqueous solution containing either chloride ions or bromide ions. Select a pair of reagents to identify which anion is present. reagentsCarry out this test and record your observations and conclusion. observationsThe anion in FA 9 is. [4] [Total: 15]UCLES 2013 9701/31/M/J/13 [Turn over<br />

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