Question

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

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

Answer 1

The correct option is A $2/5$

The balanced chemical reaction is :

$2Mn{O}_4^{-}+5C{O}_4^{2-}+16H^{+}\to 2M{n}^{2+}+5S{O}_4^{2-}+3H_{2}O$.

From the balanced chemical equation we can say that:

∵ 5 moles $S{O}_4^{2-}$ reacts with 2 moles of $KMn{O}_4$.

∴ 1 mole $S{O}_4^{2-}$ reacts with 2/5 mole of $KMn{O}_4$.

Hence, the correct option is $A$