decomposition of h2o2

1.
MnO­2 is the catalyst of the decomposition of hydrogen peroxide.

2.
In this experiment, a small amount of potassium manganate(VII) is added. In such pH of the reaction mixture, the potassium mangnate(VII) reacts with hydrogen peroxide to give colloidal manganese(IV) oxide. The equation is:
2MnO4-(aq) + 3H2O2(aq) + 2H2O(l) → 2MnO2(s) + 4H2O(l) + 2OH-(aq) + 3O2(g)
=