Heat capacities and thermodynamic properties of 2-benzoylpyridine (C12H9NO)

The heat capacities of 2-benzoylpyridine were measured with an automated adiabatic calorimeter over the temperature range from 80 to 340 K. The melting point, molar enthalpy, Delta H-fus(m), and entropy, Delta S-fus(m), of fusion of this compound were determined to be 316.49 +/- 0.04 K, 20.91 +/- 0.03 kJ mol(-1) and 66.07 +/- 0.05 J mol(-1) K-1, respectively. The purity of the compound was calculated to be 99.60 mol% by using the fractional melting technique. The thermodynamic functions (H-T-H-298.15) and (S-T-S-298.15) were calculated based on the heat capacity measurements in the temperature range of 80-340 K with an interval of 5 K. The thermal properties of the compound were further investigated by differential scanning calorimetry (DSC). From the DSC curve, the temperature corresponding to the maximum evaporation rate, the molar enthalpy and entropy of evaporation were determined to be 556.3 +/- 0.1 K, 51.3 +/- 0.2 kJ mol(-1) and 92.2 +/- 0.4 J K-1 mol(-1), respectively, under the experimental conditions.