`25mL` of a solution containing `Fe^(2+)` and `Fe^(3+)` sulphate acidifed with `H_(2)SO_(4)` is reduced by `3g` of metalllic zinc. The dsolution required `34.25mL` of `N//10` solution of `K_(2)Cr_(2)O_(7)` for oxidation. Before reduction with zinc, `25mL` of the same solution. Calculate the strength of `FeSO_(4)` and `Fe_(2) (SO_(4))_(3)` in solution.

Answer

`FeSO_(4) = 13.64g//"litre'`,
`Fe_(2)(SO_(4))_(3) = 9.45g//"litre"`