Question

$2Cr(OH{)}_3+O{H}^{-}+KI{O}_3\to 2Cr{O}_4^{2-}+5H_{2}O+KI$

The equivalent weight of $KI{O}_3$ in the given reaction is:

• A. Molecular weight
• B. $\frac{\text{molecular weight}}{3}$
• C. $\frac{\text{molecular weight}}{6}$
• D. $\frac{\text{molecular weight}}{2}$

Answer 1

The correct option is C $\frac{\text{molecular weight}}{6}$

$2Cr(OH{)}_3+O{H}^{-}+KI{O}_3\to 2Cr{O}_4^{2-}+5H_{2}O+KI$

In the above equation, the $KI{O}_3$ is converted to $KI$ where the oxidation state is changed from +5 to -1. So the number of electrons gained is 6.

The equivalent weight of $KI{O}_3$ is $\frac{\text{molecular weight}}{\text{no. of electrons gained}}=\frac{\text{molecular weight}}{6}$..

Hence, the correct option is $\text{C}$