Thermodynamics of autoionization of methanol + water mixtures

Abstract

The enthalpies of ionization of methanol + water mixtures have been measured calorimetrically and are used to calculate the entropies of autoionization. The enthalpies are analyzed in terms of the separate contributions made by transfer of methanol, water, the proton, hydroxide ions and methoxide ions from water to the mixed solvents. Comparison of the relative acidities of water and methanol in the gas phase and in water shows that in water hydroxide ions are more strongly solvated than methoxide ions.