CIE Jun 2015 v3 Paper 3 Q3

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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 identi ed 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. Before starting your practical work, halfll the 250 cm3 beaker with water. Heat it to approximately 80 C, then turn off the Bunsen burner. This will be used as a hot water bath. (a) FA 5 is the salt of another organic acid. FA 6 is a salt containing two cations and one anion from those listed in the Qualitative Analysis Notes on pages 10 and 11. Carry out the following tests and record your observations in the table below. test observations (i) (ii) (iii) To a 1 cm depth of dilute sulfuric acid in a test-tube, addve drops of potassium manganate(VII) then a small spatula measure of FA 5. Shake the tube then place it in the hot water bath. Place a spatula measure of FA 6 in a hard-glass test-tube. Heat gently and test any gas evolved with litmus paper. To a 4 cm depth of water in a boiling tube, add and dissolve a spatula measure of FA 6. Use portions of this solution, aqueous FA 6, for tests (iv)(vi).UCLES 2015 9701/33/M/J/15 [Turn over<br /> test observations (iv) To a 1 cm depth of aqueous FA 6 in a test-tube, add aqueous ammonia. (v) To a 1 cm depth of aqueous FA 6 in a test-tube, add a 1 cm depth of aqueous barium chloride followed by dilute hydrochloric acid or a 1 cm depth of aqueous barium nitrate followed by dilute nitric acid. (vi) To a 1 cm depth of aqueous FA 6 in a test-tube, add a small spatula measure of FA 5 and shake the mixture. Keep this mixture for the test in part (b). (vii) Identify as many of the ions in FA 6 as possible from your observations. FA 6 contains[9] (b) A student suggests that one of the cations in FA 6 was oxidised in test (a)(vi). (i) Name a reagent you would use tond out whether the student was correct. reagent(ii) Use your reagent to carry out a test on the mixture from (a)(vi). Record your observations below. State and explain whether the student was correct. observationsconclusion[3] [Total: 12]UCLES 2015 9701/33/M/J/15<br />

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