On the Difference between the Thermodynamic Behavior of Argon in D2O and H2O

The solubility of argon was measured in D2O (99.7%) at five temperatures: 5°, 10°, 15°, 20°, 25°C. The standard entropies, enthalpies, and free energies of solution were calculated, and compared with the corresponding values in H2O. The differences in the thermodynamic functions of solution in D2O and in H2O are interpreted in terms of the ``two-structure'' model for liquid water, and are attributed to the difference in the ``degree of crystallinity'' of the two solvents.