Temperature dependence of the solubility of non-polar gases in liquids

Potential-distribution theory and a cumulant analysis are used to derive a simple relation for the temperature dependence of the solubility of a solute in a liquid solvent. It is shown that infinite dilution thermodynamic properties at constant volume and at constant pressure can be deduced with accuracy over a broad range of temperature by just initiating two simultaneous cumulant expansions from a single state point conveniently chosen. The method is applied to the case of nitrogen in water and very good agreement is obtained with recent Henry's constant data extending from the triple point (273 K) to 10 degrees below the critical point of water (T c ⋍ 647 K). Uses and misuses of the method are presented, while the relationships with empirical correlations proposed in the literature are emphasized and discussed.