Isobaric thermal expansivity and thermophysical characterization of liquids and liquid mixtures†
Abstract
A methodology for the thermophysical characterization of liquids and liquid mixtures based on measurements of density, sound speed and isobaric heat capacity per unit volume at atmospheric pressure as a function of temperature is proposed. Density and sound speed data are used to determine the isentropic compressibility from the Laplace equation. The precision in density measurements allows one to obtain the isobaric thermal expansivity at different temperatures using an incremental procedure with quite acceptable accuracy and precision. The isothermal compressibility and isochoric molar heat capacity are both obtained from the previous properties, using well-known thermodynamic relations. The accuracy of the proposed methodology was checked by determining the above-mentioned properties for liquid