Decomposition of hydrogen peroxide by potassium permanganate.

In this experiment, potassium permanganate is reduced by hydrogen peroxide to manganese oxide (IV), which catalyzes the decomposition of hydrogen peroxide. This produces a large amount of heat that causes the water to boil and emit a large amount of oxygen.

2KMnO4 + = 2H2O + 3H2O2 2MnO2 + KOH + 3O2