CIE Jun 2017 v1 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) FA 6 is another salt of copper. The anion present is one of those listed in the Qualitative Analysis Notes. (i) Transfer a small spatula measure of FA 6 into a hard-glass test-tube. Heat gently at first, then heat strongly, until no further change occurs. Record all your observations below.(ii) Suggest the chemical formula of FA 6.[3]UCLES 2017 9701/31/M/J/17 [Turn over<br /> PMT (b) (i) Dissolve the remainder of FA 6 in an approximately 10 cm depth of distilled water in a boiling tube. FA 7 is a solution of a salt containing one anion from those listed in the Qualitative Analysis Notes. Two cations are also present. Carry out the tests described below using separate portions of solutions FA 6 and FA 7. Record your observations in the table. observations FA 6 FA 7 test To a 1 cm depth of solution in a test-tube, add an equal volume of FA 3, aqueous potassium iodide, followed by a few drops of starch indicator. To a 1 cm depth of solution in a boiling tube, add aqueous sodium hydroxide, then heat gently and carefully. To a 1 cm depth of solution in a test-tube, add a few drops of aqueous silver nitrate. To a 1 cm depth of solution in a test-tube, add aqueous ammonia. To a 1 cm depth of solution in a test-tube, add a folded 3 cm length of magnesium ribbon. (ii) What can you deduce about solution FA 7 from its reaction with magnesium? Explain your answer.UCLES 2017 9701/31/M/J/17<br /> PMT (iii) Give the ionic equation for the reaction of the metal cation in FA 7 with aqueous sodium hydroxide. Include state symbols.(iv) What type of reaction took place when aqueous potassium iodide was added to FA 7? Use your observations to help you explain your answer.(v) The observation you made when aqueous silver nitrate was added to FA 7 does not allow the anion in FA 7 to be identified with certainty. Explain why you cannot be certain about the identity of the anion.(vi) A student suggested that the anion in FA 7 could be identified with more certainty if excess ammonia solution was added after the aqueous silver nitrate. Explain why this suggestion is not correct.[11] [Total: 14]UCLES 2017 9701/31/M/J/17 [Turn over<br />

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