Question

Which of the following is disproportionation reaction?

• A. $CH _{4}+2 O _{2} \longrightarrow CO _{2}+2 H _{2} O$
• B. $CH _{4}+4 Cl _{2} \longrightarrow CCl _{4}+4 HCl$
• C. $2 F _{2}+2 OH ^{-} \longrightarrow 2 F ^{-}+ OF _{2}+ H _{2} O$
• D. $2 NO _{2}+2 OH ^{-} \longrightarrow NO _{2}^{-}+ NO _{3}^{-}+ H _{2} O$

Answer 1

Answer: (D)

Reactions in which the same substance is oxidised as well as reduced are called disproportionation reaction.

Thus, in the reaction of $NO _{2}$ and $OH ^{-}, N$ is both oxidised as well as reduced. Hence, the oxidation number increases from $+4$ in $NO _{2}$ to $+5$ in $NO _{3}^{-}$and decreases from $+4$ in $NO _{2}$ to $+3$ in $NO _{2}^{-}$.