Effect of Pressure on the Alkaline Hydrolysis of Ethyl Acetate in Acetone–Water Solutions. Parameters of Activation at Constant Volume

The effect of pressures up to 3 kbar on the rate of the base-catalyzed hydrolysis of ethyl acetate in acetone–water mixtures has been measured. From these measurements and the enthalpy and entropy of activation at constant pressure measured by others, the internal energy and entropy of activation at constant volume have been obtained as a function of solvent composition. The constant-volume parameters of activation vary with composition in a simpler way than the constant-pressure parameters. It seems likely that theoretical discussions of the solvent effect are easier if they are based on the constant-volume parameters. At low acetone concentrations, the addition of acetone reduces the rate constant at low pressure, but increases it at 3 kbar.