Prediction of the Temperature and Density Dependences of the Parameters of the Average Effective Binary Mixture Pair Potential Using Only the LIR Equation of State

Recently, using the linear isotherm regularity (LIR) equation of state, the average effective pair potential parameters for dense fluids have been calculated, and it was shown that they are only temperature dependent. Those parameters were used to propose a strong principle of corresponding states. In the present work, the approach is extended to binary mixtures, from which we have found that the average effective pair potential parameters of mixtures depend on composition and temperature. We have also calculated the average effective unlike pair potential parameters of mixtures at various temperatures via the LIR parameters. The calculated like and unlike pair potential parameters of some mixtures have then been used to calculate their excess enthalpy. When the calculated average effective pair potential parameters of mixtures are used to reduce the LIR parameters, a strong principle of corresponding states has been observed for various mixtures with different compositions, as for the pure components. The calculated like and unlike pair potential parameters have been tested with different mixing rules based on the one-fluid approximation. The maximum differences of the calculated values with the mixing rules are lower than 10%.