Influence of potential attraction term on Joule-Thomson coefficient, enthalpy and entropy of real gases

In the present work, two different intermolecular potentials are considered for the three real gases such as Ar, Kr and Xe. The effect of attraction term of the potential models on internal energy, enthalpy, entropy and JouleThomson (JT) coefficient of aforementioned gases has been investigated. To This end, the second virial coefficient of each potential was analytically derived. The suggested potential models have different attraction terms and the same repulsive terms. Our theoretical results in this work have been compared with experimental data. Our results reveal that the attraction term of the interaction potential has an important and main role to the thermodynamic properties of the selected gases. According to the results, it is found that the calculated thermodynamic function of the aforementioned gases obtained using both potential models are in acceptable agreement with available data. The degree of agreement depends strongly on the type of the used potential model and the range of pressures and temperatures. For instance, the JT coefficient of the Kr gas calculated by potential model (1) at high pressures and temperatures are in good agreement with experimental results. This property for the Ar gas has better agreement when we employ the potential model (2). This work allows us to select the suitable potential model and desired rages of pressure and temperature to give better results in comparison with experimental data.