Abstract:

On the basis of a general functional relation representing the actual PVT properties of liquids, an equation of state of the van der Waals type has heen obtained. A new equation of correlation for prediction of excess volume and excess enthalpy has been derived from the above equation as follows:
V~E=R[((~n∑_(i=1)x_iV_i+V~E)~n∑_(i=1)x_i Φ_i)/(2PV~E/T+~n∑_(i=1)x_iV_iγ_i-H~E/T)-~n∑_(i=1)(x_i Φ_i)/γ_i]
where
Φ=(γVT/R)/(1/α+2T-2P/γ)
The results of calculation of its application to 77 binary systems with 148 experimental points show that, for prediction of V~E, it is better than the Flory method and in the wide scope concerned obviously much better than the Liebermann method and, for prediction of H~E, it is generally as good as the Pollin and Fried method. The equation of correlation proposed is simple in calculation, and can be applied to multi-component systems consisting of may liquids.