Heats of Hydration and Absolute Heats of Formation of Aqueous Ions

Abstract

Accurate calculations are made for the hydration energies of the alkali halides, using the most recent data. These results, and the average of theoretical calculations made by others for the individual ions, are used to determine the most probable hydration energy of the individual ions. These in turn are the basis for calculating the absolute enthalpy of formation of aqueous H+: 98.6 kcal/g-equiv. A Born-Haber cycle can then be used to calculate the hydration energy of any other ion for which the enthalpy of the gaseous ion is known.