`1g` pure iron is dissolved in excess of `H_(2)SO_(4)`. The clear filtrate is made up `100 mL. 10mL` of this solution is treated with `0.1 M KMnO_(4)` solution till whole of the `Fe^(2+)` ions are oxidised to `Fe^(3+)` ions. Now `0.2 g Fe_(2)(SO_(4))_(3)` is dissolved in it. the solution is now treated with `Zn` and `H_(2)SO_(4)`.
The volume of `KMnO_(4)` needed to convert `Fe^(2+)` ions to `Fe^(3+)` ions in `100 mL` original solution is:

Options

A. `71 mL`
B. `142 mL`
C. `35.7 mL`
D. `80 mL`

Explanation

Meq. Of `Fe^(2+)`=Meq. Of `KMnO_(4)`
(for `100 mL` solution)
`1/56xx1000=0.1xx5xxV`
`:. V=35.7 mL`