Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

Liquidus curves of the phase diagram for the system water-dimethyl sulphoxide (DMSO) have been calculated in such a way as to give a good fit to experimental data for the phase diagram. The calculation is based on the assumption of an equilibrium chemical reaction yielding DMSO.3 H₂O, and on the relation for the excess Gibbs energy in a ternary system composed of the two starting components and their compound. The data for the temperature dependence of the difference in the heat capacities of the liquid and solid phases of the pure components in the supercooling region have been obtained by extrapolation of experimental data in the case of DMSO, and for water by adopting published data measured down to -40 °C and by estimating their further trend.