Question

The species that undergo(es) disproportionation in alkaline medium is/are :

• A. $C{l}_2$
• B. $Mn{O}_4^{2-}$
• C. $N{O}_2$
• D. $Cl{O}_4^{-}$

Answer 1

Answer: (A), (B), (C)

The correct options are
A $C{l}_2$
B $Mn{O}_4^{2-}$
C $N{O}_2$

Disproportionation is a specific type of redox reaction in which a species is simultaneously reduced and oxidised to form two different products.

In $C{l}_2$, oxidation state of $Cl$ is $0$ so it can give disproportionation reaction because $Cl$ shows oxidation state from $-1$ to $+7$.

In ${Mn{O}_4}^{2-}$, oxidation state of $Mn$ is $+6$ so it can give disproportionation reaction because $Mn$ shows oxidation state of $+2,+3,+4,+6,+7$.

In $N{O}_2$, oxidation state of $N$ is $+4$ so it can give disproportionation reaction because $N$ shows oxidation state from $-3$ to $+5$.

In ${Cl{O}_4}^{-}$, oxidation state of $Cl$ is $+7$ which is its highest oxidation state. It can be reduced so it cannot give disproportionation reaction.