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 dilution are reported for solutions of H2 in H2O and D2 in D2O at high temperatures (170∽300°C). The experimental procedure involved the use of a palladium/hydrogen (or deuterium) electrical resistance sensor. Values of KH∞ for H2–H2O solutions agree closely with published data. Values of KH∞ for D2–D2O solutions are lower than those for H2–H2O solutions. With increasing concentrations of H2 in H2O and D2 in D2O the Henry's law coefficients decrease. This is attributed to non-ideality in the gas phase.