The number of moles of `KMnO_4` that are needed to react completely with one mole of ferrous oxalate in acidic solution is

Options

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

Answer

C

Explanation

`KMnO_(4)` oxidises both `Fe^(2+)` as well as `C_(2)O_(4)^(2-)` ions.
`Fe^(2+) to Fe^(3+) + e^(-)`
`C_(2)O_(4)^(2-) to 2CO_(2) + 2e^(-)`
`MnO_(4)^(-) + 8H^(+) + 5e^(-) to Mn^(2+) + 4H_(2)O`
The overall reaction is:
`5Fe^(2+) + 5C_(2)O_(4)^(2-) + 3MnO_(4)^(-) + 24H^(+) to 3Mn^(2+) + 5Fe^(3+) + 10 CO_(2) + 12H_(2)O`
Obviously, 5 moles of ferrous oxalate react with 3 moles of `KMnO_4`. Hence, one mole of ferrous oxalate will react with `3/5` moles of `KMnO_(4)`.