Determination of vapor pressures and enthalpies of vaporization of 1,2-alkanediols

Molar enthalpies of vaporization of 1,2-ethanediol, 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, and 1,2-octanediol were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. The measured data sets were successfully checked for internal consistency. A large number of the primary experimental results on temperature dependences of vapor pressures have been collected from the literature and have been treated uniform in order to derive vaporization enthalpies at the reference temperature 298.15 K. This collection together with the experimental results reported here has helped to resolve some contradictions which have been met in the available literature.