Solubilities of inert gases and methane in H2O and in D2O in the temperature range of 300 to 600 K

Abstract

The solubility of inert gases and methane in H2O and D2O has been measured between room temperature and 600 K. The calculation of Henry’s constants k H, from the solubility data is analyzed in detail; if due account is taken of the nonideality in the gas phase, they can be determined unambiguously up to 520 K. Above this temperature, the ambiguity in k H increases sharply as contributions of third and higher order virial coefficients to the equation of state of the gaseous mixture become more important. The differences of gas solubilities in light and heavy water essentially disappear above the temperature of minimum solubility of the gases. The characteristicthermodynamic features of the aqueous solutions of gases (i.e., large values of −ΔS 0 2 and of ΔC 0 p2) are still present at 520 K. It is shown that mean‐field theories can account for the