Question

Which of the following is a catalyst that accelerates the decomposition of ${\mathrm{KClO}}_3$?

• A. ${\mathrm{MgO}}_2$
• B. $\mathrm{MnO}$
• C. $\mathrm{MgO}$
• D. ${\mathrm{MnO}}_2$

Answer 1

The correct option is D

${\mathrm{MnO}}_2$

The explanation for the correct option -

Option (D) ${\mathrm{MnO}}_2$

• Catalyst - A substance that changes the rate of a chemical reaction without itself undergoing any chemical change.
• ${\mathrm{MnO}}_2$ is a catalyst that accelerates the decomposition of ${\mathrm{KClO}}_3$

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

The explanation for the incorrect option -

Option (A) ${\mathrm{MgO}}_2$ is non-existant.

Option (B) $\mathrm{MnO}$ is not the catalyst in the reaction.

Option (C) $\mathrm{MgO}$ is not the catalyst in the reaction.

Therefore, Option (D) i.e.${\mathrm{MnO}}_2$ is the correct answer.