Solubilities of naphthalene and acenaphthene in chloro derivative solvents

The solubilities of naphthalene and acenaphthene in six chloro derivative solvents, chloroform, tetrachloromethane, 1,1-dichloroethane, 1,2-dichloroethane, trichloroethylene, and tetrachloroethylene, have been experimentally determined in the temperature range between 288 K and 323 K. This range corresponds to that which was found by us as an optimal one for the growth of crystals of these solids. The experimental activity coefficients calculated by using the classical equation for solid in liquid solubility have been compared with those predicted from the Scatchard-Hildebrand regular solution theory. For all the investigated solutions these activity coefficients are predicted to within an average of 8% in the case of naphthalene and 9% in the case of acenaphthene. As it could by expected, when the binary parameter lit determined from the lowest solubility datum point temperature has been added to the Scatchard-Hildedrand expression (extended model), the activity coefficients are predicted with substantially higher accuracy, which is 0.6% for both solids. Moreover, the root-mean-square deviations of solubility temperatures vary from 0.09 K to 10.63 K by the regular solution model and 0.07 K to 1.03 K by the extended regular solution model for all measured data.