Solvent Effect on the Enthalpy and Entropy of Activation for the Hydrolysis of Ethyl Cinnamate in Mixed Solvent System

摘要

The rate of alkaline hydrolysis of ethyl cinnamate was measured over the temperature range of 20°C to 40°C in water-acetone mixture at different composition 30 to 70% (v/v). The influence of solvent variation on reaction rate was examined in term of changes in the Activation parameter. Depletion of ?H* and ?S* value with simultaneous increase in ?G* of the reaction in reaction media, reveals that the reaction is Enthalpy domination and Entropy controlled. The Iso- dielectric activation energy (ED) of reaction was found to decrease from 52.43 to 47.28. The Values of Iso-kinetic Temperature which is less than 300, clearly indicates that there is no appreciable interaction between solvent and solute present in the reaction media, i.e., reaction is not ion-dipole but ion-molecule type.