Question

$KMn{O}_4$ gets reduced to

• A. $K_{2}Mn{O}_4$ in neutral medium
• B. $Mn{O}_2$ in acidic medium
• C. $M{n}^{2+}$ in alkaline medium
• D. $Mn{O}_2$ in neutral medium

Answer 1

Answer: (D)

$KMn{O}_4$ is a powerful oxidising agent and gets reduced to
$(i)Mn{O}_2$ in neutral medium.
$2KMn{O}_4+H_{2}O\to 2KOH+2Mn{O}_2+3[O]$
$(ii)K_{2}Mn{O}_4$ in alkaline medium.
$2KMnO4+2KOH\to 2K_{2}Mn{O}_4$
$+H_{2}O+[O]$
$(iii)M{n}^{2+}$ in acidic medium.
$Mn{O}_4^{-}+8H^{+}+5e^{-}\to M{n}^{2+}+4H_{2}O$