Regular solution theoiy

Figure 3.15. Topological features of phase diagrams calculated using regular solution theoiy.

As in vapor-liquid equilibria and in liquid-liquid equilibria, experimental mixture data are required to find liquid-phase activiqf coefficients. Fbr some solid-liquid sterns, estimates for y can be made using regular-solution theoiy (Preston and Prausnitz ) or UNIFAC (Gmehling et al., but for reliable work a few experimental measurements are necessary. 

For nonpolar systems the activity coefficient can be estimated using the Hildebtand-ScafohanI theoiy of regular solutions. To calculate the activity coefficient of a dissolved solute using regular solution theory, solubility parameters must be available for the components. For many materials these parameters can be calculated and/or are available in standard engineering references. 

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