CIE Jun 2016 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 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. Where reagents are selected for use in a test, the name or correct formula of the element or compound must be given. (a) FB 5, FB 6 and FB 7 are solutions, each of which contain one cation and one anion. The anions present are all listed on page 11. Use a 1 cm depth of these solutions in a test-tube for each of the following tests. Complete the table below. FB 5 observations FB 6 FB 7 test Add a 2 cm strip of magnesium ribbon. Add aqueous sodium hydroxide. Add an equal depth of aqueous potassium iodide. Add a few drops of FB 5.UCLES 2016 9701/34/M/J/16 [5]<br /> PMT (b) (i) From the observation made when potassium iodide was added to FB 6, suggest the identity of the cation in FB 6. Explain your conclusion. cation in FB 6explanation(ii) FB 5 gives no precipitate when aqueous ammonia is added. Suggest the identities of both ions in FB 5. cation in FB 5anion in FB 5(iii) Identify FB 7.(iv) Give the ionic equation for the reaction between magnesium and FB 7.[4] (c) FB 8 is a solid. Carry out the following tests on FB 8. Record your observations in each test. (i) Heat a small spatula measure of FB 8 gently in a hard-glass test-tube. observations(ii) To a 1 cm depth of hydrochloric acid in a test-tube, add a small spatula measure of FB 8. observations(iii) What conclusions, if any, can you make about the identities of the ions in FB 8? cation in FB 8anion in FB 8UCLES 2016 9701/34/M/J/16 [4] [Total: 13] [Turn over<br />

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