Question

The number of moles of sodium sulphite needed to react with one mole of $KMn{O}_4$ in acidic solution is :

• A. $\frac{4}{5}$
• B. $\frac{5}{2}$
• C. $1$
• D. $\frac{3}{5}$

Answer 1

The correct option is B $\frac{5}{2}$

Reaction:
$5N{a}_{2}S{O}_3+3H_{2}S{O}_4+2KMn{O}_4\to 5N{a}_{2}S{O}_4+2MnS{O}_4+K_{2}S{O}_4+3H_{2}O$
5 2
So, number of moles of sodium sulphite that reacts with one mole of $KMn{O}_4=\frac{5}{2}$.