Abstract

Sharda Soni¹* and K. D. Gupta²

pH metric titration technique has been employed to study the formation and composition of complexes of divalent Co, Ni, Cu and Zn with DL-2-amino butanedioic acid. Formation curve reveals the formation of 1:1 and 1:2 metal ligand complexes in the pH range 4.30-8.85. Their stability constant have been determined at 20°C, 30°C and 40°C and a different ionic strength viz. 0.05M, 0.1M, 0.15M and 0.2M NaClO4 by Irving Rossotti method which follow the order Co2+ < Ni2+ < Cu2+ > Zn2+ which is in agreement with Irving Williams series. The change in thermodynamic parameter DG, DH and DS accompanying complexation have been evaluated at 30°C. The stability constant and thermodynamic function of these metal complexes are discussed in relation to ionic radii, electronegativity and ionization potential of title metals.

Thermodynamics; stability of Co2+; Ni2+; Cu2+ and DL-2-amino butanedioic acid

[ View HTML Full Text]