Kinetic study of the acetate-catalysed hydrolysis of phenyl acetate

Abstract

The results of an investigation aimed at obtaining the kinetic characteristics of the hydrolysis reaction of phenyl acetate catalysed by sodium acetate are presented. The hydrolytic reaction giving phenol and acetic acid starting from phenyl acetate is particularly suitable to run in a microwave-irradiated environment. In fact, since the considered reaction is characterised by a very low rate, small variations occurring in an irradiated system can be detected. Furthermore, since this reaction runs in an aqueous environment, it can use the energy transmitted by microwave radiation efficiently, thanks to the high capacity of water absorbance at microwave frequencies. The reaction was run in a buffered aqueous solution of sodium acetate and acetic acid at equal concentrations (pH=5). Kinetic constants were obtained in the 293–318 K temperature interval and at a concentration of both sodium acetate and acetic acid in the 0.4–0.06 mol dm −3 range. The derived activation energies decreased as the concentration of the sodium acetate/acetic acid increased. The kinetic study of the hydrolysis was carried out to obtain experimental data suitable for a fast comparison with the data that will be obtained from the development of this reaction in a microwave-irradiated environment. This paper also presents the analytical and experimental techniques suitable to run the experimental procedure in a microwave-irradiated reactor.