To investigate the conversion of iron (II) ions to iron (III) ions and vice versa.

Apparatus : test tubes, boiling tube, dropper,. Test tube holder, filter funnel, Bunsen burner,

matches , spatula.

Materials : FeSO4 solution, FeCl3 solution, acidified KMnO4

solution, Zn powder, filter paper,

 NaOH solution, potassium hexacyanoferrate (II) solution, potassium hexacyanoferrate (III) solution, potassium thiocyanate solution.

Procedure of Changing iron (II) ions, Fe2+ to iron (III) ions, Fe3+

 1. Pour 4 cm³ of FeSO4 solution into a test tube.

2. Add acidified KMnO4

solution drop by drop until a yellow solution or brown solution is obtained.

3.Divide the solution obtained equally into 3 separate test tubes.

4.Test the solution with :

i.Sodium hydroxide solution

ii Potassium hexacyanoferrate (II) solution

iii.Potassium thiocyanate solution.

5.Record all the observations.

Data & observation :

II.Changing iron (III) ions, Fe3+

to iron (II) ions, Fe2+.

1.Pour 4 cm³ of FeCl3

solution into a boiling tube.

2.Add half a spatula of zinc powder and warm the mixture gently.

3.Cool the mixture and then filter it.

4.Divide the filtrate equally into 3 separate test tubes.

5.Test the solutions with :

i NaOH solution

ii Potassium hexacyanoferrate (II) solution

iii Potassium hexacyanoferrate (III) solution.

6.Record all the observations