Variation of the molar volume with the temperature and the Pippard relations near the melting point in benzene

Abstract

In this study, we calculate variation of the molar volume with the temperature at constant pressures (70.5, 85.2, 128 and 175.2 MPa) using the experimental data from the literature for the solid and liquid phases of benzene near the melting point. The calculated molar volume decreases in the solid phase as the temperature increases toward the melting temperature, whereas in the liquid phase just above the melting temperature it increases abruptly, as expected. By calculating the specific heat, thermal expansion and the isothermal compressibility from the molar volume, which increase with increasing temperature (at constant pressures), we construct the Pippard relations for the solid and liquid phases of benzene near the melting point. Our calculated molar volume and the thermodynamic quantities (specific heat, thermal expansion and the isothermal compressibility) agree to some extend with those experimental measurements from the literature for the molar volume (at 1 atm and constant pressures studied here) and the specific heat (at 0.1, 0.9 and 1.5 GPa), which also increase with increasing temperature for the solid and liquid phases near the melting point in benzene. Our calculated thermodynamic quantities and the Pippard relations can also be examined with the measurements at various temperatures at constant pressures given here near the melting point in benzene.