Solubility of 13 nonpolar gases in deuterium oxide at 15?45�C and 101.325 kPa. Thermodynamics of transfer of nonpolar gases from H2O to D2O

Abstract

Using a computer controlled version of the Ben-Naim and Baer apparatus, the solubilities of He, Ne, Ar, Kr, H2, D2, N2, O2, CH4, C2H6, C3H8, CF4, and SF6 in D2O (and the solubility of CF4 in H2O) were determined at four temperatures in the range 288 to 318 K and at a partial pressure of gas of 101.325 kPa. The precision of the measurements was 0.3–1.0%. The experimental data were processed using rigorous thermodynamic methods and were fitted to the Clarke-Glew-Weiss equation. Changes in the thermodynamic properties on solution were calculated from the smoothing equations. Scaled-particle theory (SPT) was used to determine the Lennard-Jones (6,12) pair potential parameters for D2O: σ=0.275 nm and e/k=83.4 K. Experimental mole fraction solubilities and thermodynamic functions at 298.15 K were compared with results calculated using the SPT. The thermodynamic transfer functions of gases from H2O to D2O were calculated. The changes induced by the solvation process on the structure of water were estimated from the Gibbs energy of transfer and the difference in the hydrogen bond energies for D2O and H2O.