CIE Jun 2016 v1 Paper 3 Q3

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Qualitative Analysis PMT 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. 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. FA 5 is a mixture of two different salts. Each of these salts contains one cation and one anion from those listed on pages 12 and 13. You will identify the cations and anions present. (a) (i) Carry out the following test and record your observations. test observations Place a small spatula measure of FA 5 in a hard-glass test-tube and heat strongly. Test any gases that are given off. (ii) Identify one of the cations in FA 5. One of the cations in FA 5 is. [2]UCLES 2016 9701/31/M/J/16 [Turn over<br /> PMT (b) Place the remaining sample of FA 5 in the 100 cm3 beaker. Half fill the beaker with distilled water and stir until FA 5 has fully dissolved. This may take some time. You will use this solution in the remaining tests. (i) Select reagents to identify the other cation present in FA 5. Carry out tests using these reagents and record your results in the space below. Identify the cation. The other cation in FA 5 is. (ii) Carry out the following tests and record your observations. Identify one of the anions in FA 5. test observations To a 1 cm depth of the solution of FA 5 in a test-tube add aqueous barium chloride or aqueous barium nitrate, then add dilute hydrochloric acid. One of the anions in FA 5 is.UCLES 2016 9701/31/M/J/16<br /> (iii) The remaining ion is a halide. Select a pair of reagents which can be used to identify the halide present. Carry out a test using these reagents and record your observations below. Suggest the identity of the halide anion present in FA 5. Explain why this test is not conclusive in this particular case. PMT The other anion in FA 5 is.[8] (c) Suggest the formulae of the two salts that could have been mixed to make FA 5.and[1]UCLES 2016 9701/31/M/J/16 [Turn over<br /> (d) FA 6 and FA 7 are different organic liquids. Their possible identities are listed below. 10 PMT2-methylpropan-2-ol propanal propanone Half fill the 250 cm3 beaker with water and heat to about 50 C. You will use this as a hot water bath. Turn off the Bunsen burner. Carry out the following tests and record your observations. test observations To a 1 cm depth of FA 6 in a test-tube, add a few drops of acidified potassium manganate(VII). If no reaction is seen, warm the solution in the hot water bath. To a 1 cm depth of FA 7 in a test-tube, add a few drops of acidified potassium manganate(VII). If no reaction is seen, warm the solution in the hot water bath. Suggest the identity of FA 6 and FA 7 with an explanation. FA 6FA 7[2] [Total: 13]UCLES 2016 9701/31/M/J/16<br />

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