Specific features of the solvation of gaseous n-alkanes in water H/D isotopomers

H/D isotope effects in the thermodynamic characteristics of hydration of gaseous hydrocarbons-methane, ethane, propane, n-butane, and tetrafluoromethane-were calculated on the basis of an analysis of literature data on their solubility in light and heavy water over the temperature range 278.15-318.15 K at a pressure of 0.1 MPa. Changes in the solvent structure due to the formation of the hydrocarbon-water isotopomer solvate complex were interpreted in terms of the molecular-thermodynamic concepts of "pseudo-chemical potential" and "canonical ensembles." A conclusion was made that the maximum concentrations of the gases in water decrease with an increasing structuring effect of the gas on the solvent due to the hydrophobic hydration. Specific features of the hydration of methane and n-butane are due to configurational effects in the solution.