THERMOCHEMICAL INVESTIGATIONS OF ASSOCIATED SOLUTIONS .14. CALCULATION OF ANTHRACENE BUTYL ACETATE ASSOCIATION PARAMETERS FROM MEASURED SOLUBILITY DATA

Experimental solubilities are reported for anthracene dissolved in binary solvent mixtures containing butyl acetate with n-hexane, n-heptane, n-octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane at 25.0-degrees-C. Results of these measurements, combined with estimates for the excess Gibbs free energies of the binary solvents, are used to evaluate the equilibrium constant for a presumed anthracene-butyl acetate molecular complex from the extended nearly ideal binary solvent model. A single association constant was needed to describe the experimental data to within an average deviation of 2%. The numerical value of the calculated constant varied slightly with inert hydrocarbon cosolvent, ranging from K(AC)-phi = 4.5 in 2,2,4-trimethylpentane to an upper value of K(AC)-phi = 8.0 in both cyclohexane and methylcyclohexane cosolvents.