It is confirmed experimentally that a “Diffusion controlled slow reaction model'“ explains very well the alkaline hydrolysis ofn-amyl acetate at constant inlerfacial area. Mass transfer coefficient obtained from the model agrees well with that obtained from pure mass transfer experiment. Mass transfer coefficient can be correlated against Reynolds number, Schmidt number and vessel dimensions. Effect of diluents and solutes can also be explained using the above model. From the extraction rate of H-amyl acetate dispersed in aqueous phase in an agitated vessel, the second order reaction rate constant for hydrolysis of the ester with alkali in aqueous phase is estimated based on the above model. The estimated value of second order reaction rate constant for H-amyl acetate is almost identical to that for iso-amyl acetate orn-butyl acetate.