CIE Nov 2014 v3 Paper 3 Q2

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PMT Qualitative Analysis 10 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 6 is a solid that contains one cation and one anion. One of the ions present is included in the lists on pages 14 and 15. This ion contains the element nitrogen. (i) State which nitrogen-containing ions could be present. Select reagents for use in tests that would distinguish between them.(ii) Carry out tests on FA 6 using the reagents selected in (i) to identify the nitrogen-containing ion. Record your tests and observations in the space below.UCLES 2014 9701/33/O/N/14<br /> 11 (iii) Identify the nitrogen-containing ion in FA 6. Ion present isPMT [5] (b) Halfll the 250 cm3 beaker with water and heat the water to about 60 C. This is the water bath to be used in one of the following tests. Carry out the following tests on FA 7 and complete the table below. test observations To a 1 cm depth of FA 7 in a test-tube, add a few drops of dilute hydrochloric acid. To a 1 cm depth of FA 7 in a test-tube, add a few drops of aqueous potassium iodide, then add aqueous ammonia. To a 1 cm depth of FA 7 in a test-tube, add a few drops of aqueous sodium hydroxide and then add aqueous ammonia dropwise, with gentle shaking, until the precipitate just dissolves, then add one spatula measure of glucose and leave to stand in the hot water bath. When you have completed this test, dispose of the solution and rinse the test-tube. No observation required. [4]UCLES 2014 9701/33/O/N/14 [Turn over<br /> PMT 12 (c) Solid FA 8 contains one cation and one anion from those included in the lists on pages 14 and 15. Carry out the following tests on FA 8. For each test record your observations. (i) In a hard-glass test-tube heat approximately half of the FA 8, gently atrst and then more strongly. Leave to cool.(ii) To a 2 cm depth of dilute nitric acid in a boiling tube, add the remaining FA 8. Keep the solution obtained for tests (iii) and (iv).(iii) To a 1 cm depth of the solution from (ii) in a test-tube, add aqueous sodium hydroxide until no further change occurs.(iv) To a 1 cm depth of the solution from (ii) in a test-tube, add aqueous ammonia until no further change occurs.(v) Use your observations from (i) to (iv) to identify the ions present in FA 8. Ions presentand[6] [Total: 15]UCLES 2014 9701/33/O/N/14<br />

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