CIE Nov 2017 v6 Paper 3 Q2

Answers available below

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 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.UCLES 2017 9701/36/O/N/17 [Turn over<br /> FB 5, FB 6 and FB 7 are aqueous solutions that each have an ion containing one of the metals from those listed in the Qualitative Analysis Notes. (a) Carry out the following tests and record your observations. test observations PMT (i) To a 1 cm depth of FB 5 in a test-tube add a 1 cm depth of aqueous sodium hydroxide, then add several drops of hydrogen peroxide. (ii) To a 1 cm depth of FB 6 in a test-tube add aqueous sodium hydroxide. (iii) (iv) (v) To a 1 cm depth of FB 6 in a test-tube add several drops of hydrogen peroxide and then add aqueous sodium hydroxide. To a 1 cm depth of FB 6 in a test-tube add a 1 cm depth of dilute sulfuric acid and then add a few drops of FB 7. To a 1 cm depth of FB 6 in a test-tube add a 1 cm depth of FB 7. (vi) To a 1 cm depth of aqueous potassium iodide in a test-tube add a few drops of FB 7, then add a few drops of aqueous starch. (b) Identify the metal present in FB 5, FB 6 and FB 7. FB 5 containsFB 6 containsFB 7 contains[8] [3]UCLES 2017 9701/36/O/N/17<br /> PMT (c) What do your observations in (a)(vi) tell you about what has happened to the iodide ions on addition of FB 7 to KI(aq)? You may give your answer in the form of an equation.[1] (d) (i) FB 8 is a solid sample of the compound present in aqueous solution FB 7. Heat all of FB 8 in a hard-glass test-tube gently for about 10 s and then strongly for about 20 s. observations(ii) Leave the test-tube and contents to cool completely. To the cooled test-tube add a 1 cm depth of aqueous sodium hydroxide. Observe the appearance of the contents of the test-tube. appearance[2] (e) FB 6 contains one of the anions Cl , Br , I, SO4 2 or SO3 2. (i) Construct a table to show reagents you would use to identify which anion is present in FB 6. Include in your table space to record your observations and deductions. (ii) Carry out your tests on FB 6 until you have identified the anion. Record your observations and deductions in your table.UCLES 2017 9701/36/O/N/17 anion in FB 6 =[3] [Total: 17] [Turn over<br />

Show answer