Thermodynamic properties of water under pressure up to 5 kbar and between 28 and 120 °C. Estimations in the supercooled region down to −40 °C

Abstract

The heat liberated by isothermal compression permits the determination of the thermodynamic properties of liquid water−heat capacity, compressibility, and expansivity. The results, as a function of pressure and temperature, have been extrapolated as far down as −40 °C. They confirm the existing data in the region of the supercooled liquid and also the existence of a divergence of the measured properties. This could be explained as a lambda transition occuring at −45 °C on isobars p = 0. The abnormal heat capacity which characterizes this transition is well described as a function of the temperature by a formula with critical coefficients as already suggested by others.