Question

Assertion: $CI{O}_4^{-}$ does not show disproportionation reaction.
Reason : In $Cl{O}_4^{-},$ chlorine is present in its highest oxidation state.

• A. If both assertion and reason are true and reason is the correct explanation of assertion.
• B. If both assertion and reason are true but reason is not the correct explanation of assertion.
• C. If assertion is true but reason is false.
• D. If both assertion and reason are false.

Answer 1

Answer: (A)

A disproportionation reaction is a reaction in which a compound undergoes both oxidation and reduction. In oxidation, the oxidation number of $n$ element increases, and in reduction, the oxidation number of the element decreases.
$Cl{O}_4^{-}$does not show any disproportionation reaction, because it undergoes only reduction and not oxidation. This is because the oxidation state of $Cl$ in $Cl{O}_4^{-}$ion is $+7$. It is the maximum oxidation state that chlorine can have. It can decrease its oxidation number by undergoing reduction but not increase it anymore.
Hence, $Cl{O}_4^{-}$ion does not show disproportionation reaction.