The Thermal Pressure and Energy–Volume Coefficients of Dimethyl Sulfoxide – Water Mixtures

Thermal pressure and energy–volume coefficients are reported for several DMSO–water mixtures over the temperature range 13–55 °C. The energy–volume coefficient at 25 °C is found to pass through a maximum at 0.3–0.4 mole fraction DMSO and this observation is rationalized in terms of maximization of intercomponent interactions. The relationship between the energy–volume coefficient and the cohesive energy density of the binary liquid system is examined. The temperature dependence of the thermal pressure coefficient is discussed in terms of the effect of temperature on the susceptibility of the entropy of DMSO–water mixtures to isothermal expansion.