Low-temperature heat capacities and thermodynamic properties of 1-methyl-3,5-diphenyl-pyrazole

The heat capacities of 1 - methyl - 3,5 - diphenyl - pyrazole have been precisely determined with a small sample precision automated adiabatic calorimeter over the temperature range from 78 to 370 K. A phase transition from solid to liquid is observed at the peak temperature of (332.903 +/- 0.152) K. The molar enthalpy and entropy of the phase transition as well as chemical purity of the substance are determined to be (17463.48 +/- 21.81) J . mol(-1), (52.55 +/- 0.06) J .K-1. mol(-1) and 99.54%, respectively, on the basis of the heat capacity measurements. The further research of solid - liquid phase transition for this compound has been carried out by means of DSC technique.