Question

When a manganous salt is fused with a mixture of $KN{O}_3$ and solid $NaOH$, the oxidation number if Mn changes from $+2$ to:

• A. $+4$
• B. $+3$
• C. $+6$
• D. $+7$

Answer 1

Answer: (C)

$+6$

The balanced chemical equation representing the reaction between $M{n}^{+2}$ and a mixture of $KN{O}_3$ and $NaOH$ is given by:

$MnS{O}_4+2NaOH+KN{O}_3\to N{a}_{2}Mn{O}_4+KN{O}_2+H_{2}O+S{O}_2$

The oxidation number of $Mn$ in $N{a}_{2}Mn{O}_4$ is $+6$