Question

Acidified $KMn{O}_4$ solution is decolourized by

• A. bleaching powder
• B. white vitriol
• C. Mohr's salt
• D. laughing gas

Answer 1

Answer: (C)

Acidified $KMn{O}_4$ solution is decolourized by Mohr's salt and Mohr's salt is $FeS{O}_4{\left(N{H}_4\right)}_{2}S{O}_4\cdot 6H_{2}O$
$Mn{O}_4^{-}+8H^{+}+5e^{-}\to M{n}^{2+}+4H_{2}O$
$5F{e}^{2+}\to 5F{e}^{3+}+5e^{-}$
$Mn{O}_4^{-}+8H^{+}+5F{e}^{2+}\to \underset{(Colourless)}{M{n}^{2+}}+4H_{2}O+5F{e}^{3+}$