Analytic Equations of State of Simple Liquids and Liquid Mixtures

Based on the variational and perturbation theories of liquid state, at equilibrium conditions, an approximation technique is introduced through which it has been made possible the derivation of analytic relations for the thermodynamic properties of simple liquids in which the intermolecular potential can be represented by the Lennard-Jones (m-n) potential function. By the application of the hard-sphere expansion (HSE) conformal solution theory it has been possible to generalize the resulting relation of pure systems for the miwtures of simple liquids, and, consequently, analytic relations for the total and the excess thermodynamic properties of liquid mixtures are derived. For a numerical case study, the equations of state derived are applied to the systems for which the LennardJones (b-12) potential function is assumed to be valid and the results are compared with the experimental values and the results of the other theories of liquids and liquid mixtures.