Question

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

• A. $2/5$
• B. $3/5$
• C. $4/5$
• D. $1$

Answer 1

The correct option is A $2/5$

Reaction:

$6H^{+}+2Mn{O}_4^{-}+5S{O}_3^{2-}\to 2M{n}^{2+}+5S{O}_4^{2-}+3H_{2}O$

So one mole of sulphite ion will need 2/5 moles of KMnO₄