HYDROGEN-BONDING AND PHASE-EQUILIBRIUM

The thermodynamics of the mobile order of H-bonding in liquids considers not the various H-bonded or non-H-bonded entities present in the solution. but the fraction of time (1 - gamma) during which an OH proton follows the electron-donor site of another molecule in its walk through the liquid. The influence of the H-bonds on the free energy of the system is given by G(h) = n RT ln gamma. The time fraction (1 - gamma) is ruled by the concentration of the sites and by equilibrium constants which may differ from those of Guldberg and Waage. Quantitative expressions are derived for the effect of solvent-solvent and solute solvent H-bonds on the solubility of crystalline substances with carbonyl or ether groups. At 25-degrees-C the predictions agree within 10% with the experimental values.