25 mL of a solution containing Fe2+ and Fe3+ sulphate acidified with H2SO4 is reduced by 3g of metallic zinc. The solution required 34.25 mL of N/10 solution of K2Cr2O7 for oxidation. Before reduction with zinc, 25 mL of the same solution required 22.45 mL of same K2Cr2O7 solution. Calculate the strength of FeSO4 and Fe2 (SO4 ) 3 in g/lit