CIE Nov 2015 v5 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 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. 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) FA 6 is a sodium compound containing one anion listed on page 11. Dissolve the FA 6 provided in about 15 cm3 of distilled water in a boiling tube. Carry out the following tests and record your observations in the table below. test observations (i) To a 1cm depth of the solution of FA 6 in a test-tube, add a few drops of aqueous barium chloride or aqueous barium nitrate, then add dilute hydrochloric acid. (ii) To a 1cm depth of the solution of FA 6 in a test-tube, add an equal volume of aqueous hydrogen peroxide, then add a few drops of aqueous barium chloride or aqueous barium nitrate, then add dilute hydrochloric acid.UCLES 2015 9701/35/O/N/15 [Turn over<br /> PMT observations test To a 1 cm depth of the solution of FA 6 in a boiling tube, add an equal volume of FA 2, sulfuric acid, then heat the mixture gently and cautiously. To a 1 cm depth of the solution of FA 6 in a test-tube, add an equal volume of aqueous sodium hydroxide, then add a few drops of FA 1, aqueous potassium manganate(VII), then (iii) (iv) add FA 2, sulfuric acid. (v) Identify the anion in FA 6, and state one piece of evidence for your identi cation. anionevidence(vi) Give the chemical equation for the reaction between FA 6 and hydrogen peroxide, H2O2, in test (ii). State symbols are not required.[7]UCLES 2015 9701/35/O/N/15<br /> (b) FA 7, FA 8, FA 9 and FA 10 each contain one cation from the list on page 10. You will attempt to identify the cations by testing with aqueous sodium hydroxide and aqueous ammonia. In each case, use a 1 cm depth of the solution in a test-tube. (i) Complete the table below. PMT FA 7 FA 8 FA 9 FA 10 observations test add sodium hydroxide add aqueous ammonia (ii) Use your observations to identify, as far as possible, the cation present in each solution. If alternative identities are possible, state this clearly. FA 7 cationFA 8 cationFA 9 cationFA 10 cation(iii) Give the ionic equation for the reaction of one of your cations with a few drops of sodium hydroxide. State symbols are not required.(iv) The precipitates obtained when alkalis are added to solutions of certain cations are sometimes dif cult to see. Suggest how, using no additional apparatus, the experiment could be repeated in a way that would make these precipitates more visible.[9]UCLES 2015 9701/35/O/N/15 [Total: 16] [Turn over<br />

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