The molar heat capacity of the azeotropic mixture composed of water and benzene was measured by an adia-batic calorimeter in the temperature range from 80 to 320 K. The phase transitions took place in the temperature range from 265.409 to 275.165 K and 275.165 to 279.399 K. The phase transition temperatures were determined to be 272.945 and 278.339 K, which were corresponding to the solid-liquid phase transitions of water and benzene, respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to stan-dard temperature 298.15 K were derived from the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.
Low-temperature heat capacities of pyrimethanil decylate(C22H33N3O2) were precisely measured with an automated adiabatic calorimeter over the temperature range from 78 to 373 K. The sample was observed to melt at（311.04±0.06） K. The molar enthalpy and entropy of fusion as well as the chemical purity of the compound were determined to be（45876±12） J/mol, （147.50±0.05） J·mol -1 ·K -1 and （99.21±0.03）%（mass fraction）, respectively. The extrapolated melting temperature for the absolutely pure compound obtained from fractional melting experiments is （311.204±0.035） K.
SUN Xiao-hongLIU Yuan-faTAN Zhi-chengWANG Mei-hanJIA Ying-qi
