CIE Jun 2017 v4 Paper 3 Q2

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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) (i) FB 5, FB 6 and FB 7 each contain one anion and one cation. Carry out the following tests and record your observations. FB 5 observations FB 6 FB 7 test To a 1 cm depth of solution in a test-tube, add a few drops of aqueous silver nitrate, then add aqueous ammonia. To a 1 cm depth of solution in a test-tube, add a few drops of aqueous barium nitrate, or barium chloride, then add dilute nitric acid. To a 1 cm depth of solution in a test-tube, add a spatula measure of solid sodium carbonate.UCLES 2017 9701/34/M/J/17 [Turn over<br /> PMT (ii) What cation is present in FB 5, FB 6 and FB 7? 10(iii) Suggest another test that you could carry out to confirm the presence of the cation you identified in (ii). Carry out this test on one of FB 5, FB 6 or FB 7 and record your observation. testobservation(iv) Complete the table to identify, as far as possible, the anions present in FB 5, FB 6 and FB 7. If you are not able to identify the anion from the tests you carried out in (i), write unknown. FB 5 FB 6 FB 7 ion present (v) For any one anion that you were unable to identify in (iv) you are to devise a test or tests that will enable you to identify it. You can assume that it is one of the anions listed in the Qualitative Analysis Notes. Carry out the test(s), record the observation(s) you obtained and identify the unknown anion. test(s)observation(s)Anion present inis. [10]UCLES 2017 9701/34/M/J/17<br /> 11 (b) FB 8 is an aqueous solution of a mixture containing two anions and two cations. Carry out the following tests and record your observations. PMT observations test To a 1 cm depth of FB 8 in a test-tube, add a 1 cm depth of dilute hydrochloric acid, then add a few drops of hydrogen peroxide, then add a few drops of starch. To a 1 cm depth of FB 8 in a test-tube, add aqueous sodium hydroxide. To a 1 cm depth of FB 8 in a test-tube, add a 3 cm depth of aqueous copper(II) sulfate, then add a 1 cm depth of dilute hydrochloric acid, then add aqueous sodium thiosulfate. From these observations, identify two ions present in FB 8. ions present in FB 8and[5] [Total: 15]UCLES 2017 9701/34/M/J/17 [Turn over<br />

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