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. FA 6, FA 7 and FA 8 are solutions of salts. Information about FA 6, FA 7 and FA 8 • Each salt contains one cation and one anion. • One of the ions is sodium; the other five ions are listed in the Qualitative Analysis Notes. • Each salt contains a different nitrogen-containing ion. • FA 7 or FA 8 contains a halide ion.

1. (a)You will identify the cations present in FA 6, FA 7 and FA 8. To do this you will carry out six separate tests. You will use dilute sulfuric acid and aqueous sodium hydroxide separately with FA 6, FA 7 and FA 8. Use a 1 cm depth of each salt solution in a suitable tube for each test you carry out. Record all of your observations in a table in the space below.[4]
2. (b)Name the reagents you would use to identify the halide ion present in either FA 7 or FA 8. Test FA 7 and FA 8 with these reagents and record your observations. reagents used ..............................................................[2]
3. (c)(i)Name the reagents you would use to confirm the presence of the nitrogen-containing anions in the two solutions that do not contain a halide ion. Test both solutions with these reagents and record your observations. reagents used ..............................................................[2]
4. (c)(ii)Name the reagent you would use to positively identify one of the nitrogen-containing anions in the two solutions tested in (i). Test both solutions with this reagent. Record all your observations. reagent used ..............................................................[2]
5. (d)Use the information given in (a) and your observations in all tests to deduce the chemical formulae of the three salts. FA 6 is .............................................. FA 7 is .............................................. FA 8 is ..............................................[2]