Thermodynamic behaviour of liquid p-xylene near freezing

Abstract

Experimental pρT measurements and derived thermodynamic properties of p-xylene (1,4-dimethylbenzene) have been obtained with an expansion technique for temperatures between 288 and 303 K and pressures up to 43 MPa, or freezing pressure when lower. The solid-liquid coexistence curve of this compound was also measured up to 40 MPa. The experimental results have been correlated in terms of a recently derived equation of state, which is introduced here and has been used to calculate the isothermal compressibility, κ_T, and the thermal expansion coefficient, α_p, as functions of pressure and temperature. The equation of state depends only on six parameters, all of which are physically meaningful. Comparisons of several properties show good agreement with literature values.