CIE Jun 2017 v3 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 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) FA 6 and FA 7 are aqueous solutions. Each solution contains one cation and one anion from those listed in the Qualitative Analysis Notes. Use 1 cm depths of FA 6 or FA 7 in test-tubes for the following tests. Complete the table by recording your observations. observations FA 6 FA 7 test Add a few drops of aqueous barium chloride or aqueous barium nitrate, then add dilute nitric acid. Add a few drops of aqueous silver nitrate. Add a small spatula measure of sodium carbonate. Shake the mixture. (ii) From your observations, deduce which solution, FA 6 or FA 7, has the lower pH. Give your evidence. solution with lower pHevidence[4]UCLES 2017 9701/33/M/J/17<br /> (b) Choose two reagents that would allow you to identify the cations in FA 6 and FA 7. reagentsandUse these reagents to test solutions FA 6 and FA 7. Record all your observations in the space below. PMT (c) Deduce the chemical formulae of FA 6 and FA 7. FA 6FA 7[4] [2] [Total: 10]UCLES 2017 9701/33/M/J/17 [Turn over<br />

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