THERMOPHYSICAL PROPERTIES OF SUBSTANCES ON THE BASIS OF INTEGRATED EQUATIONS FOR PARTIAL DISTRIBUTION FUNCTIONS

In order to design and optimize a chemical engineering process a researcher should be aware of different physical and chemical properties of the substances involved in this process. The spectrum of such properties is rather wide. They make up two big groups combining equilibrium and non-equilibrium characteristics. Since certain limitations to empirical and semi-empirical methods have been found, one way for solving this problem could be the molecular-statistic theory approaches whereby any thermodynamic properties can be defined from the data on interaction between atoms and molecules of the substance. Results and discussion 1. The description for equilibrium characteristics of liquids and gases. It is beyond doubt that the the basis of statistical physics is formed by the method of Gibbs ’ ensembles. With this method, it is possible to link Helmholtz free energy with total molecular energy in the system [1]: