Question

What is the use of manganese dioxide in the laboratory preparation of oxygen gas?

Answer 1

• In the laboratory, oxygen is prepared from the Hydrogen peroxide$\left({\mathrm{H}}_2{\mathrm{O}}_2\right)$ which is added drop by drop from a funnel to Manganese dioxide$\left({\mathrm{MnO}}_2\right)$.
• $\underset{\mathrm{Hydrogen}\mathrm{peroxide}}{2{\mathrm{H}}_2{\mathrm{O}}_2\left(\mathrm{l}\right)}\stackrel{{\mathrm{MnO}}_2}{\to }\underset{\mathrm{Water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}$
• Manganese dioxide is used as a catalyst in this reaction.
• Catalyst- A catalyst is a substance added to the reaction which increases or decreases the rate of reaction without itself undergoing any change.