Question

Assertion (A) In the reaction between potassium permanganate and potassium iodide, permanganate ions act as oxidising agent.
Reason (R) Oxidation state of manganese changes from $+2$ to $+7$ during the reaction.

• A. Both $A$ and $R$ are correct; $R$ is the correct explanation of $A$.
• B. Both $A$ and $R$ are correct; $R$ is not the correct explanation of $A$.
• C. $A$ is correct; $R$ is incorrect.
• D. $A$ is incorrect; $R$ is correct.

Answer 1

Answer: (C)

The reaction of potassium permanganate and potassium iodide is as follows :
$10KI+2K\stackrel{+7}{\mathrm{Mn}}{O}_4+8H_{2}S{O}_4⟶2\stackrel{+2}{\mathrm{Mn}}S{O}_4+6K_{2}S{O}_4+8H_{2}O+5I_2$
Oxidation state of Mn decreases from $+7$ to $+2$.
Thus, $A$ is correct but $R$ is incorrect.