Potentiometric Studies on Binary complexes of La (III) ion with Quinaldic Acid

Abstract

The binary solid complex of La(III) ion with Quinaldic Acid was isolated from the mixture of equimolar solutions of metal nitrates and ligand. The pH of the solution was adjusted to 7.0. The equimolar solution was refluxed in ethyl alcohol for about 3-4 hours on water bath. On refluxing, the solid mass is obtained on cooling. This solid mass was filtered, washed, recrystallized and dried at 60-70°C. The complex was subjected to elemental analysis. The metal content present in complex was estimated by conventional standard methods. The probable formula of complex was assigned on the basis of elemental analysis, which was well supported by TG curves. The kinetic parameters like activation energy (Ea), Order of reaction (n), frequency factor (log Z) and activation Entropy (S°) were calculated by applying Doyle’s method modified by Zsako (2) and Coat's and Redfern methods.