The number of moles of acidified `KMnO_4` required to convert one mole of sulphite ion into sulphate ionis:

Options

A. `2//5`
B. `3//5`
C. `4//5`
D. `1`

Answer

A

Explanation

`underset(2" moles")( 2 MnO_(4)^(-) )+ 6 H^(+) + underset(5" moles")(5SO_(3)^(2-)) to 2 Mn^(2+) + 5SO_(4)^(2-) + 3H_2 O`
5 moles of ` SO_(3)^(2-) ` = 2 moles of ` MnO_(4)^(-)`
1 mole of `SO_(3)^(2-)` = 2/5 moles of ` MnO_(4)^(-)`
` -= 2//5` moles of `KMnO_(4)`