A small amount of `MnO_2` is added to `H_2O_2` taken in a test tube.
a) Suggest an experiment to identify the gas liberated.
b) Write the chemical equation of the reaction taking place?
c) What is the role of `MnO_2` in the chemical reaction.

Explanation

a) Introduce a glowing match stick in to the test tube. Flaring up of the glowing match stick shows the presence of oxygen.
b) .2H_2O_2 rarr 2H_2O + O_2.
c) .MnO_2. increases the rate of reaction. Hence it acts as a positive catalyst.