Question

Which of the following species do not show disproportionation reaction?

• A. $Cl{O}^{-}$
• B. $Cl{O}_4^{-}$
• C. $Cl{O}_2^{-}$
• D. $Cl{O}_3^{-}$

Answer 1

Answer: (B)

$Cl{O}_4^{-}$ does not disproportionate because in this oxo anion chlorine is present in its highest oxidation state $(+7)$. The disproportionation reactions for the other three oxo anions of chlorine are as follows :
$\stackrel{\text{+1}}{3C}l{O}^{-}\to \stackrel{\text{-1}}{2C}{l}^{-}+\stackrel{\text{+5}}{\mathrm{Cl}}{O}_3^{-}$
$\stackrel{\text{+3}}{6C}l{O}_2^{-}\stackrel{hv}{\to }\stackrel{\text{+5}}{4C}l{O}_3^{-}+\stackrel{\text{-1}}{2C}{l}^{-}$
$\stackrel{\text{+5}}{4C}l{O}_3^{-}\to \stackrel{\text{-1}}{C}{l}^{-}+\stackrel{\text{+7}}{3C}l{O}_4^{-}$