FORMATION-CONSTANTS OF TERNARY COMPLEXES OF SOME HEAVY-METAL IONS WITH N-(2-ACETAMIDO)IMINODIACETIC ACID AND ALIPHATIC OR AROMATIC-ACIDS

Solution equilibria of the ternary systems involving La(III), Y(III), Ce(III), and UO22+, N-(2-acetamido)iminodiacetic acid, and some alipha tic or aromatic acids have been investigated potentiometrically The fo rmation of 1:1:1 mixed ligand complexes is inferred from the potentiom etric titration curves. Formation constants of the different binary an d ternary complexes formed in such systems were determined at 25 +/- 0 .1-degrees-C and mu = 0.1 mol dm-3 (KNO3). It is deduced that the mixe d ligand complexes are more stable than the corresponding binary compl exes containing the aliphatic or aromatic acidate moiety. The order of stability of the binary and ternary complexes is investigated and dis cussed in terms of the nature of both the metal ion and the secondary ligand (aliphatic or aromatic acid).