The equilibrium constants for the liquid-phase dehydration of 1-octanol to 1-(octyloxy)octane (DNOE) and water have been determined in the temperature range (413 to 453) K over Amberlyst 70. The equilibrium constants for the main side reactions, intramolecular dehydration of 1-octanol to 1-octene and 1-octene isomerization to 2-octene, have been determined as well. Etherification of 1-octanol was shown to be exothermic, with reaction enthalpy change of (-13.6 +/- 1.7) kJ.mol(-1) at 298.15 K The standard formation enthalpy of 1-(octyloxy)octane was computed to be (-581 +/- 2) kJ.mol(-1), in good agreement with the estimated value by a modified Benson method. A standard molar entropy of (658 +/- 4) J.mol(-1).K-1 in the liquid phase has been found for 1-(octyloxy)octane from the entropy change of reaction at 298.15 K. Intramolecular dehydration of 1-octanol has been found to be endothermic and isomerization of 1-octene to 2-octene exothermic.