A contribution to the problem of thermodynamic similarity of H 2O and D 2O

Abstract

The paper reports the results of p-v-T measurements of D 2O in the region of 500 to 3500 bar, 80 to 350°C, and the results of measurements of the Joule-Thomson effect of H 2O and D 2O in that of 1.2 to 1.8 bar, 130 to 190°C. An analysis and comparison with data of other investigators indicate that the measurements conducted in the region of high pressures are accompanied by limit errors of ±15 bar, ±0.2°C, ±0.0015 cm 3/g, and that of the Joule-Thomson effect by a limit error of ±0.03°C/bar. A presentation is made of Jůza's equation of state which very well describes the experimental data of H 2O in the investigated regions. The above information has been used for checking the validity of the Van der Waals theorem of corresponding states in the respective regions. The theorem was found to be valid within the limits of the errors of measurement in the region of the measured Joule-Thomson effect lying in the vicinity of the saturation line. Deviations exceeding the errors of measurement found to exist in the region of high pressures, were expressed in the equation of state by correction terms describing the real values within the limits of the errors of measurement.