The equilibrium constants for the liquid-Phase dehydration reaction between I-octanol and ethanol to 1-ethoxyoctane (EOE) and water and the dehydration reaction between two ethanol molecules to ethoxyethane (DEE) and water were determined over Amberlyst 70 in the temperature range (410 to 463) K in a batch reactor. Both reactions were greatly shifted to products at the chemical equilibrium. In particular, product concentrations found for EOE synthesis were higher than those measured for DEE,:formation. Besides, both liquid-phase etherification reactions proved to be exothermic, with a reaction enthalpy change of (-18.9 +/- 1.3) kJ.mol(-1) for EOE synthesis and (-13.1 +/- 0.9) kJ.mol(-1) for DEE one, at 298 K. The EOE standard formation enthalpy value of (-436 +/- 7) kJ.mol(-1), in good agreement with the estimated value by a modified Benson method, and the EOE standard molar entropy value in the liquid phase of (434 +/- 11) J.mol(-1).K-1, slightly underestimated by the Benson method, are found.