Question

In the following reaction,
$Cr(OH{)}_3+O{H}^{-}+I{O}_3^{-}\to Cr{O}_4^{2-}+H_{2}O+I^{-}$
Choose the incorrect statement:

• A. $I{O}_3^{-}$ is oxidising agent
• B. $Cr(OH{)}_3$ is oxidised
• C. $6$ electrons are being taken up per $I$ atom
• D. The above reaction is not a redox reaction

Answer 1

The correct option is D The above reaction is not a redox reaction

In the given reaction,
$Cr(OH{)}_3+O{H}^{-}+I{O}_3^{-}\to Cr{O}_4^{2-}+H_{2}O+I^{-}$
The oxidation number of $I$ changes from $+5$ to $-1$.
Thus, each iodine takes $6$ electrons and is reduced.
Hence, $I{O}_3^{-}$ is the oxidising agent.
Oxidation number of chromium changes from $+3$ to $+6$.
Thus, $Cr(OH{)}_3$ is oxidised.
(d) The given reaction is a redox reaction.