Question

The number of moles of $KMnO_{4}$ reduced by one mole of $KI$ in alkaline medium is

• A. one-fifth
• B. five
• C. one
• D. two

Answer 1

Answer: (D)

two

Answer 2

In alkaline solution, $KMnO _{4}$ is reduced to $MnO _{2}$ (colourless). $\frac{2 KMnO _{4}+2 H _{2} O \longrightarrow 2 MnO _{2}+2 KOH+3[ O ] KI +3[ O ] \longrightarrow KIO _{3}}{2 KMnO _{4}+2 H _{2} O + Kl \longrightarrow 2 MnO _{2}+2 KOH + KlO _{3}}$ Hence, two moles of $KMnO _{4}$ are reduced by one mola of $KI$