THERMOCHEMICAL INVESTIGATIONS OF HYDROGEN-BONDED SOLUTIONS - DEVELOPMENT OF A PREDICTIVE EQUATION FOR THE SOLUBILITY OF ANTHRACENE IN BINARY HYDROCARBON PLUS ALCOHOL MIXTURES BASED UPON MOBILE ORDER THEORY

Experimental solubilities are reported for anthracene dissolved in twe lve binary solvent mixtures containing either 2-propanol or 1-octanol with n-hexane, n-heptane, n-octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane at 25.0 degrees C. Results of these measuremen ts, along with previously published solubility data for anthracene in binary 1-propanol + alkane and 1-butanol + alkane mixtures, are used t o test the limitations and applications of expressions derived from Mo bile Order theory. The best descriptive equation expresses the logarit hm of the volume fraction solubility in binary mixtures as a simple vo lume fraction average of the corresponding logarithm solubilities in t he two pure solvents, and contains additional terms to represent contr ibutions from nonspecific physical interactions between dissimilar sol vent components, from molecular size disparity, and from the reduction in mobile disorder caused by the self-association by hydrogen bonding of the alcohol solvent. The newly derived expression predicts the obs erved anthracene solubilities to within an overall average deviation o f ca. 4.4% using a single value of K-C= 5000 for the self-association equilibrium constant.