Kinetics Study of Co-Solvent effect in Alkaline Hydrolysis of Diethyl Pathalate Ester

The base catalyzed hydrolysis of diethyl pathalate has been carried out titrometically in water-ethanol binary solvent mixture covering range of 30 to 70% (v/v) of solvent composition at different Temperature (20 to 400C). The reaction followed second order rate constant which decreases with increase of solvent composition. The salvation and desolvation concept are used to explain the solvent influence on rate and mechanism is the reaction. The relation between changes in dielectric constant due to variation of reaction mixture and change in specific rate constant has been explained on the basis of electrostatic and non-electrostatic contribution of solvent mixture. Calculated value of Iso-composition activation energy is found to be increases with increase of solvent composition. The thermodynamic parameters (G*, H*&S*) has been determined with help of Wynne Jone and Eyring equation which show the great dependency on solvent composition.