Thermodynamic Properties Study for the Binary Mixtures of Acetonitryle+ Dichloroethane, Trichlorethan at Temperature Range of 293.15-303.15 K: Experimental Results and Application of the Prigogine–Flory–Patterson Theory

In the present work, densities, ρ, and viscosities, η, for binary mixture of (x1 acetonitryle+x2 dichloroethane) and (x1 acetonitryle +x2 trichlorethan) have been measured at atmosphericpressure and in the entire composition range. These quantities have been used to calculate excessmolar volumes, V(E)(m) These excess and deviation quantities have then been fitted to the Redlich–Kister equation [1]. The obtained correlations were used to calculate the other thermodynamicfunctions such as thermal expansion coefficient, α, and its excess value, α(E), and isothermalcoefficient of excess molar enthalpy (∂H(E)(m) /∂P)T,x. Results of such calculations were used forinterpreting intermolecular interactions that exist between molecules of the binary mixture,qualitatively. The Prigogine-Flory-Patterson (PFP) theory has been successful in prediction thevolumetric properties of various kinds of binary mixtures [2,3]. In this theory, excessthermodynamic properties of a binary mixture are separated into three contributions: theinteractional contribution which is proportional to the interaction parameter, χ12; free volumecontribution which arises from the difference between size of two components; and pressurecontribution which depends on the internal pressure and reduced volume of the components. Inthis work, we have investigated the PFP theory as a method to predict the V(E)(m) of these binarymixtures. Results of these calculations were used for interpreting intermolecular interactions thatexist between molecules of the binary mixture. The densities of these binary mixtures weremeasured over the temperature range and over the entire composition range. Data of the excessmolar volumes for these binary mixtures were calculated from the values of the experimentaldensity. The calculated excess molar volumes using the PFP model are comparable withexperimental values [4,5].