The equilibrium constants of the liquid-phase dehydration of 1-hexanol to dihexyl ether (DNHE) and water were determined in the temperature range of (423 to 463) K on Amberlyst 70. The equilibrium constants of the two main side reactions, DNHE decomposition to 1-hexene and 1-hexanol and isomerization of 1-hexene to 2-hexene, were also studied. The etherification reaction proved to be slightly exothermic, with an enthalpy change of reaction of -(9.5 +/- 0.2) kJ.mol(-1) at 298 K. From this value, the standard formation enthalpy and molar entropy of DNHE were computed to be -(478.6 +/- 0.8) kJ.mol(-1) and (517.4 +/- 0.5) J.K(-1).mol(-1), respectively. A correction concerning the effect of pressure on the entropy proved to be necessary when computing liquid-phase entropy from gas-phase data. The isomerization of 1-hexene to 2-hexene is exothermic, whereas the decomposition of DNHE is endothermic.