CIE Nov 2014 v4 Paper 3 Q3

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PMT colour changes seen the formation of any precipitate the solubility of such precipitates in an excess of the reagent added Qualitative Analysis At each stage of any test you are to record details of the following.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) You will carry out further experiments with aqueous hydrogen peroxide, FB 3. FB 2 is dilute sulfuric acid, H2SO4. FB 3 is aqueous hydrogen peroxide, H2O2. FB 6 is a solution containing two cations and one anion. FB 7 is a solution containing one cation and one anion. (i) To a 1 cm depth of FB 6 in a boiling tube, add aqueous sodium hydroxide until it is in excess. Then heat the tube, gently and with care. Keep the mixture for test (ii). Record your observations. Identify the cations in FB 6. observationsFB 6: cations areand(ii) To the mixture obtained from (i) add a 1 cm depth of FB 3. Shake the tube. Record your observations. observationsWhat type of reaction has taken place? Explain your answer.UCLES 2014 9701/34/O/N/14 [Turn over<br /> PMT (iii) To a 1 cm depth of FB 3 in a test-tube, add an equal volume of sulfuric acid, FB 2. Then add a 1 cm depth of FB 7, followed by a few drops of starch solution. Record all your observations. Draw what conclusions you can about the ions in FB 7. If no conclusion is possible, write not known. observationsFB 7: cationanion[7] (b) FB 7, FB 8 and FB 9 are aqueous solutions, each containing one cation and one anion. Note that FB 7 was also used in (a)(iii). (i) Carry out the following tests in test-tubes. Use 1 cm depths of solutions. Complete the table by recording your observations. test FB 7 observations FB 8 FB 9 add a 2 cm strip of magnesium ribbon FB 7 FB 8UCLES 2014 9701/34/O/N/14<br /> PMT (ii) Suggest the identify of the cation in FB 9. Explain your answer. cationexplanation(iii) Give the ionic equation for the reaction between FB 7 and FB 9.(iv) From your observations, identify FB 8.[6] [Total: 13]UCLES 2014 9701/34/O/N/14 [Turn over<br />

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