CIE Jun 2017 v2 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 reagents are selected for use in a test, the name or correct formula of the element or compound must be given. Where gases are released they should be identified by a test, described in the appropriate place in your observations. You should indicate clearly at what stage in a test a change occurs. 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. (a) FB 5 and FB 6 are solutions of acids of equal concentration in mol dm3. One solution is a weak acid and the other is a strong acid. (i) Devise and carry out a chemical test to find out which of FB 5 and FB 6 is the weak acid. Record your test, observations and conclusion in the space below.UCLES 2017 9701/32/M/J/17<br /> (ii) Another acid, FB 7, is a dilute solution of one of hydrochloric, nitric or sulfuric acids. Carry out the tests in the order given in the table below until you are able to identify FB 7. Record your observations. If any test is unnecessary write not needed. test observations PMT To a 1 cm depth of FB 7 in a test-tube add aqueous silver nitrate. To a 0.5 cm depth of FB 7 in a boiling tube add a 1 cm depth of aqueous sodium hydroxide and a small piece of aluminium foil and warm. To a 1 cm depth of FB 7 in a test-tube add aqueous barium chloride or aqueous barium nitrate. FB 7 isacid. [6]UCLES 2017 9701/32/M/J/17 [Turn over<br /> 10 (b) FB 8 contains a cation listed in the Qualitative Analysis Notes. FB 9 is a solution of an organic salt. Carry out the following tests and record your observations. test observations PMT (i) To a 1 cm depth of FB 8 in a test-tube add aqueous sodium carbonate. (ii) To a 1 cm depth of FB 8 in a test-tube add a 1 cm depth of aqueous potassium iodide, then add aqueous sodium thiosulfate until in excess. (iii) To a 2 cm depth of FB 8 in a test-tube add a 1 cm depth of concentrated hydrochloric acid (CARE). Keep this solution for test (iv). (iv) To a 2 cm depth of distilled water in a boiling tube add all the contents of the test-tube from test (iii). Keep this solution for tests (v) and (vi). Pour a 1 cm depth of the contents of the boiling tube into three separate test-tubes for use in tests (v) and (vi). One tube is to be used for comparing colours in your observations. (v) To one of the test-tubes add aqueous ammonia until in excess. (vi) To a second test-tube add FB 9 until in excess.UCLES 2017 9701/32/M/J/17<br /> PMT 11 (vii) Identify the cation in FB 8. cation(viii) Write an ionic equation for a precipitation reaction you observed during your experiments with this cation. Include state symbols.[8] [Total: 14]UCLES 2017 9701/32/M/J/17 [Turn over<br />

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