Reduction of potassium permanganate

Chemicals needed

diluted potassium permanganate solution

sulphuric acid 10%  Xi   R 36/38    S (1/2)-26-30-45

hydrogen peroxide solution 3.5%

Equipment needed

test tube

Test procedure

• Safety goggles!
• One adds about 0.5 ml diluted potassium permanganate solution to a test tube and then adds approx. 0.5 ml of diluted sulphuric acid.
• Now one adds 1 ml hydrogen peroxide solution 3.5%. Together with somewhat of a gas formation the solution is rapidly declorized.

Disposal

Elucidation

Hydrogen peroxide can be oxidized in an acid milieu with the strongly oxidizing agent Mn(VII), hereby Mn(II) and elementary oxygen are produced.

2 MnO4- + 6 H+ + 5 H2O2 --> 2 Mn2+ + 5 O2 + 8 H2O

Literature

derived from experiment 3., "KMnO4 + H2O2", p.82, [7]