Reactions of Sulphites

Experiment 1

Acidify about 2 cm³ of aqueous sodium sulphite with an equal volume of dilute sulphuric acid.

Add aqueous potassium manganate (VII), KMnO₄, dropwise.

Record your observations and write equations for any reactions.

Experiment 2

Acidify about 2 cm³ of aqueous sodium sulphite with an equal volume of dilute sulphuric acid.

Add aqueous potassium dichromate, K₂Cr₂O₇, dropwise.

Record your observations and write equations for any reactions.

Experiment 3

To 2 cm³ of sodium sulphite solution in a boiling tube add an equal volume of freshly prepared Fe³⁺ solution. Then add excess dilute sodium hydroxide solution.

Add sodium hydroxide solution to the original Fe³⁺ solution in a test-tube.

Record your observations and write equations for any reactions.

Experiment 4

Place 2 cm³ of sodium sulphite solution in a test-tube and add an equal volume of barium chloride solution.

Then acidify with dilute hydrochloric acid.

Record your observations and write equations for any reactions.

Experiment 5

Add aqueous iodine solution dropwise to sodium sulphite solution.

Record your observations and write equations for any reactions.