The Reaction Rate of the Alkaline Hydrolysis of Ethyl Acetate

The reaction rate of the alkaline hydrolysis of ethyl acetate was studied by means of a continuous measurement of the electric conductivity change. The second-order rate constant decreased as the reaction proceeded. The decrease was evident when the initial concentrations of the ester and the base were close together. The initial rate constant at 25°C was measured as 0.1120 1./mol./sec. and the activation energy was 11.56 kcal./mol., values agreed well with those of previous studies. From the standpoint of the electronic theory of organic chemistry, Day and Ingold proposed a sequential reaction mechanism passing through an addition complex. The results of the approximate calculations to the pseudo-first-order reaction and the analog-computation of the exact models coincided with the experimental results. The difference in the activation energies of the forward and reverse reaction rates was calculated from the experimental data. At lower temperatures this reverse reaction rate was small, and the overall reaction rate was approximated as a pure second-order reaction. Other probable reasons for the rate constant decrease were also discussed.