Question

Which of the following is used as a catalyst in the decomposition of potassium chlorate$\left({\mathrm{KClO}}_3\right)$?

• A. Potassium chloride
• B. Oxygen
• C. Sulphur dioxide
• D. Manganese dioxide

Answer 1

The correct option is D

Manganese dioxide

The explanation for the correct option -

Option (D) Manganese dioxide

• Catalyst - A catalyst is a substance that changes the rate of a chemical reaction without itself undergoing any chemical change.
• In the decomposition of potassium chlorate$\left({\mathrm{KClO}}_3\right)$, Manganese dioxide$\left({\mathrm{MnO}}_2\right)$ is used as a catalyst.

$\underset{\mathrm{Potassium}\mathrm{chlorate}}{2{\mathrm{KClO}}_3\left(\mathrm{s}\right)}\stackrel{\mathrm{Manganese}\mathrm{dioxide}\left({\mathrm{MnO}}_2\right)}{\to }\underset{\mathrm{Potassium}\mathrm{chloride}}{2\mathrm{KCl}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{3{\mathrm{O}}_2\left(\mathrm{g}\right)}$

The explanation for the incorrect option -

Option (A) Potassium chloride - It is formed by the decomposition of potassium chlorate.

Option (B) Oxygen - It is formed by the decomposition of potassium chlorate.

Option (C) Sulphur dioxide

Therefore, Option (A) i.e. Potassium chloride is the correct answer.