The reaction kinetics and the chemical equilibrium of the consecutive, reversible liquid-phase e esterification of ethylene glycol with acetic acid to ethylene glycol monoacetate and ethylene glycol diacetate using the acidic ion-exchange resin Amberlyst 36 as catalyst were investigated. Kinetic experiments were accomplished for various temperatures and starting compositions of the reactants and products in the temperature range from 333.15 to 363.15 K. The experimental results of the heterogeneous catalyzed esterification and of the hydrolysis as backward reaction were used to derive a pseudohomogeneous model which is able to describe the reaction rate of the five-component system starting from any initial composition. Based on a pseudohomogeneous attempt, the applicability of mole fractions and activities for the description of the reaction rates as a function of time were compared.