Question

In which one of the following sets all species show disproportionation reaction?

• A. $ClO _{2}^{-}, F _{2}, MnO _{4}^{-}$and $Cr _{2} O _{7}^{2-}$
• B. $Cr _{2} O _{7}^{2-}, MnO _{4}^{-}, ClO _{2}^{-}$and $Cl _{2}$
• C. $MnO _{4}^{-}, ClO _{2}^{-}, Cl _{2}$ and $Mn ^{3+}$
• D. $Cr _2 O _7^{2-}, MnO _4^{-} ClO _2^{-} \text {andCl }{ }_2$

Answer 1

Answer: (C)

Disproportionation reactions are a special type of redox reactions. One of the reactants in a disproportionation reaction always contains an element that can exist in at least three oxidation states. The element of reacting species is in intermediate oxidation state and simultaneously gets oxidised and reduced $MnO _4^{-}$do not shows disproportionation reaction.