Question

The number of moles of `KMnO_(4)` that will be needed to react with one mole of sulphite ion in acidic solution is :
A. `(4)/(5)`
B. `(2)/(5)`
C. `1`
D. `(3)/(5)`

Answer 1

Correct Answer - B
The redox reaction is :
`2MnO_(4)^(-)+5SO_(3)^(2-)+6H^(+) to 2Mn^(2+) + 5SO_(4)^(2-)+3H_(2)O`
1 mole `SO_(3)^(2-)` will be oxidised by `(2)/(5)` mol of `MnO_(4)^(-)`