Thermochemical investigations of nearly idial binary solvents. 6. Solubilities of iodine and benzil in systems of nonspecific interactions

Abstract

Solubilities have been determined at 25°C for iodine in binary mixtures of carbon tetrachloride with cyclohexane, n-hexane, n-heptane, and octamethylcyclotetrasiloxane (OMCTS) and in mixtures of cyclohexane with n-hexane and OMCTS; and for benzil in binary mixtures of carbon tetrachloride with cyclohexane, n-hexane, and n-heptane, mixtures of n-hexane with cyclohexane and n-heptane, and mixtures of benzene with cyclohexane and toluene. With the exception of the benzene+cyclohexane system, the nearly ideal binary solvent model predicts these solubilities with a maximum deviation of 6% and an overall standard deviation of 2.4%. The model correctly predicts minima for solubility (mole fraction) of iodine in the OMCTS systems, and predicts solubilities within 4% for benzil in the carbon tetrachloride+n-hexane system, in which the solubility changes by a factor of 14. The failure of the model for predicting solubilities of benzil in mixtures of benzene and cyclohexane (maximum error of 25% for and 18-fold range of solubilities) is possibly due to specific interactions between benzil and benzene.