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
