Henry's law constant for hydrogen in natural water and deuterium in heavy water

The results of measurements of the Henry's law constant near infinite dilut ion are reported for solutions of H-2 in H2O and D-2 in D2O at high tempera tures (170 similar to 300 degreesC). The experimental procedure involved th e use of a palladium/hydrogen (or deuterium) electrical resistance sensor. Values of K-H(infinity) for H-2-H2O solutions agree closely with published data. Values of K-H(infinity) for D-2-D2O solutions are lower than those fo r H-2-H2O solutions. With increasing concentrations of H-2 in H2O and D-2 i n D2O the Henry's law coefficients decrease. This is attributed to non-idea lity in the gas phase.