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") (2MnO_4^-) + 6H^+ + underset ("5 moles ") (5SO_3^(2-))to 2Mn^(2+) + 5SO_4^(2-) + 3H_2O`
`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`