NONLINEAR DEPENDENCE OF THE SOLUBILITY OF WATER IN HYDROCARBONS ON THE MOLAR VOLUME OF THE HYDROCARBON

The solubility of water in fifty hydrocarbon solvents at 20 degrees C is estimated by means of the solubility equation derived from the ther modynamics of mobile order in H-bonded liquids. Neglecting the change in nonspecific cohesion forces, and assuming that water is primarily m onomeric in solution, the prediction accounts for two main effects: th e breaking of the H-bond network linking the water solute molecules to gether and the entropy of exchange between water and solvent molecules in solution. The formation of a weak O-H ... pi hydrogen bond interac tion is moreover taken into account according to whether the hydrocarb on is saturated or not. The overall predictive equation foresees a non -linear dependence of the water solubility on the molar volume of the hydrocarbon, Several rules are presented regarding the water solubilit y-hydrocarbon structure relationship.