Which of the following species do not show disproportionation reaction?
- $\mathrm{BrO}^{\ominus}$ (hypobromite ion)
- $\mathrm{BrO}_{2}^{\ominus}$ (bromite ion)
- $\mathrm{BrO}_{3}{ }^{\ominus}$ (bromate ion)
- $\mathrm{BrO}_{4}{ }^{\ominus}$ (perbromate ion)
Solution
$\mathrm{Br}$ is present in its highest oxidation state, i.e., $+7$. The disproportionation for other three oxoanions of $\mathrm{Br}$ is as follows:
$3 \stackrel{+1}{\mathrm{Br}} \mathrm{O}^{\ominus} \longrightarrow 2 \stackrel{-1}{\mathrm{Br}}^{\ominus}+\stackrel{+5}{\mathrm{Br}}\mathrm{O}_{3}^{\ominus}$
$6 \stackrel{+3}{\mathrm{Br}} \mathrm{O}_{2}^{\ominus} \stackrel{h v}{\longrightarrow} 4 \stackrel{+5}{\mathrm{Br}} \mathrm{O}_{3}^{\ominus}+\stackrel{-1}{2\mathrm{Br}}^{\ominus}$
$4 \stackrel{+5}{\mathrm{Br}} \mathrm{O}_{3}^{\ominus} \longrightarrow 3 \stackrel{+7}{\mathrm{Br}} \mathrm{O}_{4}^{\ominus}+\stackrel{-1}{\mathrm{Br}}^{\ominus}$
Asked in: JEE-TOPICTESTS-CHEMISTRY