In the preparation of $\mathrm{KMnO}_{4}$ pyrolusite $\left(\mathrm{MnO}_{2}ight)$ is first converted to…
In the preparation of $\mathrm{KMnO}_{4}$ pyrolusite $\left(\mathrm{MnO}_{2}ight)$ is first converted to potassium manganate $\left(\mathrm{K}_{2} \mathrm{MnO}_{4}ight)$. In this conversion, the oxidation state of manganese changes from
$+1$ to $+3$
$+2$ to $+4$
$+3$ to $+5$
$+4$ to $+6$
Solution
In $\mathrm{MnO}_{2}$ (O.S. of $\mathrm{Mn}$ is $\left.+4ight)$ in $\mathrm{K}_{2} \mathrm{MnO}_{4}$ (O.S.of Mn is +6). Hence O.S. changes by 2 .