THE ISOCHORIC-HEAT, ISOBARIC-HEAT AND SATURATION-HEAT CAPACITIES OF THE LENNARD-JONES FLUID FROM EQUATIONS OF STATE AND MONTE-CARLO SIMULATIONS

Isochoric-, isobaric- and saturation-heat capacities are calculated fr om the modified Benedict-Webb-Rubin type equation of state (EOS) of Jo hnson et al. (1993) and from the van der Waals theory based EOS given by Mecke et al. (1995) for the Lennard-Jones fluid. The isochoric- and isobaric-heat capacities are also determined from NVT and NpT ensembl e Monte Carlo simulations. A method is proposed for the determination of the saturation heat capacity using the appropriate fluctuation form ulae in both ensembles. The EOS-based theoretical results show reasona ble agreement with the simulation data. Comparing with real liquids th e theoretical heat capacities based on EOSs, calculated along the vapo ur-liquid saturation curve, agree well with experimental data for argo n and methane.