The order of esterification reaction of acetic acid and ethanol catalyzed by Fe2(SO4)3.7H2O and CusO4.5H2O has been determined. The reaction order was found to be 2 with respect to acid and ethanol with constant quantities of catalysts. The activity of catalysts can be expressed by Ym value, which is different from catalyst to catalyst. For Fe2(SO4)3.7H2O, Cr2(SO4)3.6H2O, CuSO4.kH2O, NiSO4.7H2O, ZnSO4.7H2O, CoSO4.7H2O, FeSO4.7H2O and MnSO4.5H2O the Ym values are 1.52, 1.21, 0.62, 0.42, 0.47, 0.25, 0.10 and 0.00 respectively. A linear relationship of Ym with the fraction of the second ionization potentiol (P) over radius (r) of metal ion of sulphate salts was found to be Ym=α(P/γ)+b.

Key words: ETHANOL, CATALYST, ESTERIFICATION, ACTIVITY, SULFATE, HYDRATE, ACETIC ACID, ACTIVATION ENERGY