Question

What is the function of manganese dioxide?

Answer 1

It is a catalyst!

Explanation:

Manganese dioxide (`MnO_2`) can also be called manganese (IV) oxide . This ionic compound can catalyze the decomposition of hydrogen peroxide.

Catalysts decrease the activation energy for chemical processes.

In the video below `MnO_2` (black powder) has been added to a test tube containing `H_2O_2` (clear liquid). The reaction that takes place is written as follows:

`2H_2O_2 -> 2H_2O + O_2`

A bamboo skewer is lit on fire using a candle, then blown out. Lowering the still glowing end into the test tube where the reaction is taking place causes the bamboo to start burning again because of the oxygen which is being created by the reaction.

`MnO_2` can also be used to make other manganese compounds (`KMnO_4`), in organic synthesis and a pigment.

Hope this helps!