In order to oxidise a mixture of one mole of each of `FeC_2O_4,Fe_2(C_2O_4)_3,FeSO_4 and Fe_2(SO_4)_3` in acidic medium , the number of mole of `KMnO_4` required is

Options

A. `2`
B. `1`
C. `3`
D. `1.5`

Answer

A

Explanation

`FeC_2O_4 hArrFe^(2+)+C_2O_4^(2-)`
`10Fe^(2+)+2MnO_4^(-) +16H^(+)rarr10Fe^(2+)+2Mn^(2+)+8H_2O`
`5C_2O_4^(2-)+2MnO_4^(-)+16H^(+)rarr2Mn^(2+)+10CO_2+8H_2O`
For 1 mol of `C_2O_4^(2-)` mol of `KMnO_4` is needed
For mol of `C_2C_2O_4` , 2/5 mol of `KMnO_4` is needed
`:.` For 1 mol of `FeC_2O_4` , moles of `KMnO_4` needed
`=2/10+2/5=6/10`
`Fe_2(C_2O_4)_3hArr2Fe^(3+)+3C_2O_4^(2-)`
For 3 mol of `C_2O_4^(2-)` , moles of `KMnO_4` needed
`=3xx2/5=6/5`
`Fe^(3+)` is not affected by `KMnO_4`
`FeSO_4 hArrFe^(2+)+SO_4^(2-)`
1 mol of `Fe^(2+)` require `KMnO_4=2/10` mol
`Fe_2(SO_4)_3` is not affected by `KMnO_4` .
Total moles of `KMnO_4` required
`=6/10+6/5+2/10=(6+12+2)/10=2` moles