Thermodynamics Research Center / ThermoML | Thermochimica Acta

ABSTRACT

Molar enthalpies of sublimation of 1,2-dihydroxybenzene, 1,3-dihydroxybenzene, and 1,4- dihydroxybenzene were obtained from the temperature dependence of the vapour pressure measured by the transpiration method. The molar enthalpies of fusion of 1,2- and 1,4-isomers were measured by DSC. A large number of the primary experimental results on temperature dependences of vapour pressures and phase transitions have been collected from the literature and have been treated uniform in order to derive sublimation, vaporization and fusion enthalpies of dihydroxybenzenes at the reference temperature 298.15 K. The data sets on phase transitions were checked for internal consistency. This collection together with the new experimental results reported here has helped to resolve contradictions in the available thermochemical data and to recommend consistent and reliable sublimation, vaporization and fusion enthalpies for all three isomers under study.