OPTIMIZATION OF UNIQUAC STRUCTURAL PARAMETERS FOR INDIVIDUAL MIXTURES- APPLICATION TO NEW EXPERIMENTAL LIQUID-LIQUID EQUILIBRIUM DATA FOR AQUEOUS-SOLUTIONS OF METHANOL AND ETHANOL WITH ISOAMYL ACETATE

Experimental liquid-liquid equilibrium data for the ternary mixtures w ater + methanol + isoamyl acetate and water + ethanol + isoamyl acetat e at various temperatures are reported, together with the results of c orrelation by the original UNIQUAC equation using both structural para meters q and r from the literature and q's and r's optimized for each mixture as part of the overall correlation procedure. The improved fit obtained with the optimized parameters (which differed from the ''uni versal'' values only for the smaller molecules) may be viewed as being due to the active surface area and volume of a molecule being depende nt upon its environment.