CIE Jun 2013 v3 Paper 3 Q3

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Examiners For Use 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. (a) You are provided with a solid, FA 5. FA 5 is a mixture that contains two anions and two cations. To all your sample of FA 5 in a boiling tube add 3 cm depth of distilled water. Shake the tube andlter the contents. Keep the solid residue for tests in (b) and theltered solution for tests in (c). (b) (i) Open up thelter paper and scrape the residue into a boiling tube. Add dilute nitric acid, HNO3, using a dropping pipette until the solid just disappears. Record your observations and keep the solution for tests in (ii). observations(ii) Divide the solution from test (i) equally into three test-tubes. To therst test-tube add aqueous sodium hydroxide, NaOH, until in excess. Record your observations. observationsWhich cations, from those listed in the Qualitative Analysis Notes on page 12, would give these observations?UCLES 2013 9701/33/M/J/13<br /> Examiners For Use (iii) You are to devise tests that will positively identify which one of the cations you have suggested in (ii) is present. For each of the possible ions you should indicate the test and the expected result for each test in a suitable table in the space below. Use the solutions in the second and third test-tubes to carry out these tests and record your observations in the space below. Identify the cation present. The cation present is. [7]UCLES 2013 9701/33/M/J/13 [Turn over<br /> Examiners For Use 10 (c) To 1 cm depth ofltered solution from (a) in a test-tube add 1 cm depth of dilute nitric acid followed by a few drops of aqueous silver nitrate. Record your observation. observationWhich further reagent could be added to this test-tube to help you to con rm the nature of the anion present? reagentCarry out a test using this additional reagent. Record your observation and conclusion about the anion present. observationThe anion present is. (d) Using your observation in (b)(i) state which other anion is present in FA 5. The anion present is. [2] [1]UCLES 2013 9701/33/M/J/13<br /> Examiners For Use (e) Solutions FA 6 and FA 7 each contain one of the ions sul te, SO3 2, sulfate, SO4 2, nitrite, NO2 , or nitrate, NO3 . 11 (i) Carry out the tests in the table below to identify which ion is present in each solution. observations FA 6 FA 7 test To 1 cm depth of solution in a boiling tube, add a small piece of aluminium foil and 1 cm depth of aqueous sodium hydroxide. Warm the mixture with care. To 1 cm depth of solution in a test-tube, add a few drops of aqueous barium chloride or barium nitrate, then add dilute hydrochloric acid. To 1 cm depth of solution in a test-tube, add 1 cm depth of dilute hydrochloric acid. (ii) From your observations, identify the anion present in each solution. FA 6 containsFA 7 contains(iii) What type of reaction takes place when a positive observation is seen with aluminium foil and aqueous sodium hydroxide in (i)?[5]UCLES 2013 9701/33/M/J/13 [Total: 15] [Turn over<br />

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