Backone family of equations of state: 2. Nonpolar and polar fluid mixtures

In the BACKONE equations the Helmholtz energy F is written as the sum F = F -H + F-A + F-D + F-Q, where F-H is the hard-body contribution, F-A the attr active dispersion force contribution, F-D the dipolar, and F-Q the quadrupo lar contribution In Part I of this article (Muller et al, 1996a) the constr uction of BACKONE and its application to pure fluids were presented. In the extension to mixtures, for each term of F a specific mixing rule is used. This concept requires only one adjustable state-independent binary mixture parameter To demonstrate the feasibility of this approach, predictions of p hase equilibria, including a liquid-liquid equilibrium and other thermodyna mic properties, are given for 20 binary fluid mixtures from the groups: non polar + nonpolar; nonpolar + dipolar; nonpolar + quadrupolar; and polar + p olar.