Test 1(a):

• Place 10 drops of solution Q in a test tube

• Add Sodium Hydroxide solution, dropwise with gentle shaking, until in excess

• Do not discard this mixture

• Repeat this test with solution R and then solution S

• Record your results in a suitable table

Test 1(b):

• Half fill a 250ml beaker with freshly boiled water

• Allow the four test tubes containing the mixtures from test 1 (a) to stand in the beaker of hot water for about 10 minutes

• Record your results in a suitable table

Test 2:

• Place 10 drops of Sodium Carbonate solution in a test tube

• Add 10 drops of solution Q and shake the mixture gently

• Repeat this procedure with solution R and then solution S

• Record your results in a suitable table

Test 3:

• Place 10 drops of solution Q in a test tube

• Add 10 drops of Silver Nitrate solution and shake the mixture gently

• Repeat this procedure with solution R and then solution S

• Allow the four test tubes to stand for 10 minutes

• Record your results in a suitable table

Theory:

Transitions metals absorb some frequencies of visible light as electrons jump to higher orbitals. Meaning the complex ions formed are usually coloured.

Transition metals form insoluble metal hydroxides when they react with Sodium Hydroxide, we can identify the metal from the colour of the precipitate.

Fe³⁺(aq) + 30H^-(aq) → Fe(OH)₃(s)

Iron (III) will from a yellow/ brown precipitate.

Cu²⁺(aq) + 20H^-(aq) → Cu(OH)₂(s)

Copper (II) will produce a blue precipitate

Fe²⁺(aq) + 20H^-(aq) → Fe(OH)₂

Iron (II) will produce a green precipitate