Partial molar volumes of organic solutes in water. IV. Benzoic and hydroxybenzoic acids at temperatures from T=298 K to T=498 K and pressures up to 30 MPa

Density data for dilute aqueous solutions of benzoic acid and three hydroxy benzoic acids obtained in the temperature range 298.15 K to 498.15 K and at either atmospheric pressure or at pressures close to the saturated vapour pressure of water and at elevated pressures up to 30 MPa are presented alon g with partial molar volumes calculated from the experimental data. The dat a were obtained by using both a high-temperature high-pressure flow vibrati ng-tube densimeter and a commercial vibrating-tube cell DMA 602HT. (C) 2000 Academic Press.