Prediction of solubilities, the effect of temperature on the solubility of n‐alkanes, and the mobile order theory

Abstract

ABSTRACT:The solubility equation derived from the thermodynamics of mobile order theory was used (1) to predict the solubility of three solid n-alkanes-octadecane, dotriacontane, and hexatriacontane-in nonassociated and self-associated liquids at 25°Cand (2) to predict the increased solubility in particular solvents with increasing temperatures. The evolution of the predicted solubility rested on the relative importance of the different terms contributing to the solubility. Generally, the fluidization of the solute presented a reluctance to the solubility. In nonassociated liquids, the balance of placing the entropy correction and the change in the nonspecific cohesion forces played up, whereas in the hydrogen-bonded liquids, the solubility was determined by the hydrophobic effect. The effect of increasing the temperature of the dissolution of the solute was a reduction in the negative fluidization and nonspecific cohesion forces, which resulted in increased solubility.