CIE Jun 2015 v4 Paper 3 Q3

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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) FB 4 and FB 5 are solutions of salts each containing one cation and one anion from those listed in the Qualitative Analysis Notes on pages 10 and 11. Carry out the following tests and record your observations in the table below. observations FB 4 FB 5 test (i) To a 1 cm depth of solution in a test-tube, add aqueous ammonia. (ii) To a 1 cm depth of solution in a test-tube, add a few drops of aqueous silver nitrate. (iii) To a 1 cm depth of solution in a test-tube add a few drops of aqueous barium chloride or barium nitrate.UCLES 2015 9701/34/M/J/15 [Turn over<br /> (iv) Identify both ions in FB 4. cationanion(v) Suggest the ions which may be present in FB 5. cationsanions(vi) Select a reagent which could be used in a further test on FB 5 to identify the cation present. Carry out your test and record your observations. test observations To a 1 cm depth of FB 5 in a test-tube, addThe cation in FB 5 is[7] (b) FB 6 is a pale purple salt containing two cations. (i) What does this suggest about the identity of one of the cations in FB 6?UCLES 2015 9701/34/M/J/15<br /> Carry out the following tests and complete the table below. test observations (ii) Place a spatula measure of FB 6 in a hard-glass test-tube. Heat gently. (iii) (iv) Dissolve a small spatula measure of FB 6 in a 2 cm depth of distilled water in a test-tube. Use this solution for tests (iv) and (v). Pour about half the solution prepared in (iii) into a boiling tube and add aqueous sodium hydroxide, then gently warm the mixture. (v) the remainder of in the To (iii), solution prepared add a few drops of aqueous potassium iodide, then add a few drops of starch solution. (vi) Identify the cations present in FB 6. FB 6 containsand(vii) What type of reaction occurred when potassium iodide was added to FB 6 in (v)?[7]UCLES 2015 9701/34/M/J/15 [Total: 14]<br />

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