Question

Potassium permanganate acts as an oxidant in neutral, alkaline as well as acidic media. The final products obtained from it in the three conditions are, respectively :

• A. $Mn{O}_4^{2-},M{n}^{3+}$ and $M{n}^{2+}$
• B. $Mn{O}_2,Mn{O}_2$ and $M{n}^{2+}$
• C. $Mn{O}_2,Mn{O}_2^{+}$ and $M{n}^{2+}$
• D. $MnO,Mn{O}_2$ and $M{n}^{2+}$

Answer 1

Answer: (B)

$Mn{O}_2,Mn{O}_2$ and $M{n}^{2+}$

The final products obtained from potassium permanganate in the three conditions are, respectively $Mn{O}_2,Mn{O}_2$ and $M{n}^{2+}$.
In neutral and in alkaline medium, the reaction is as shown below:
$Mn{O}_4^{-}+2H_{2}O+3e^{-}\to Mn{O}_2+4O{H}^{-}$.
In acidic medium, the reaction is as shown below.
$Mn{O}_4^{-}+8H^{+}+5e^{-}\to M{n}^{2+}+4H_{2}O$.