Different species of Fe(III)-galic (FeHL, FeL2, FeL3) acid complexes are formed at different pH values These species have different rates of reduction with ascorbate. By measuring the overall rates of reduction of Fe(III) to Fe(II) at different pH and using the calculated species distribution at the corresponding pH a graphical procedure was applied to obtain the bimolecular rate constants for reduction of indivudal complex species. These were k(FeHL) = 87.9, k(FeL) = 113 and k(FeL2) = 4 all in units of M-1S-1.


S ARIF KAZMI ,ZAHIDA T MAQSOOD ,