CIE Jun 2014 v4 Paper 3 Q3

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PMT 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) A different sample of limestone was reacted with dilute nitric acid to give solution FB 6. This sample of limestone contained calcium carbonate, CaCO3, and one other salt. This additional salt contains a single cation and a single anion from those listed on pages 11 and 12. By carrying out the following tests you will be able to suggest identities of the additional ions. test observations (i) To a 1 cm depth of FB 6 in a test-tube add aqueous ammonia. (ii) To a 1 cm depth of FB 6 in a test-tube add a 1 cm depth of aqueous silver nitrate. (iii) To a 1 cm depth of FB 6 in a test-tube add a 1 cm depth of aqueous barium chloride or barium nitrate.UCLES 2014 9701/34/M/J/14<br /> PMT (iv) Suggest all possible identities for the ions present in FB 6, apart from Ca2+ and NO3 .(v) Select a reagent to use in a further test on FB 6 to con rm that one of the cations you have listed in (iv) is not present in FB 6. Carry out your test and complete the table. test observations conclusion To a 1 cm depth of FB 6 in a test-tube add[6] II III IV VI (b) You are provided with a solid, FB 7. By carrying out the following tests you will be able to identify three of the ions present in FB 7. test observations (i) Place a spatula measure of FB 7 in a hard-glass test-tube. Heat gently atrst, then heat more strongly until no further change is seen, then allow the tube to cool.UCLES 2014 9701/34/M/J/14 [Turn over<br /> 10 test observations PMT II III IV VI VII (ii) Place a spatula measure of FB 7 in a test-tube. Add about a 5 cm depth of dilute nitric acid. You will use the solution formed for tests (iii) to (v). (iii) To a 1 cm depth of the solution in a test-tube add a few drops of aqueous potassium manganate(VII), then add a few drops of starch solution. (iv) To a 1 cm depth of the solution in a test-tube add a few drops of aqueous silver nitrate. (v) To a 1 cm depth of the solution in a test-tube add aqueous ammonia. Use the Qualitative Analysis Notes on pages 11 and 12 to identify three of the ions present.[7] [Total: 13]UCLES 2014 9701/34/M/J/14<br />

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