Densities of cresols and linear alkane mixtures at high pressure

This work reports experimental densities for o-, m-, and p-cresol and the m-cresol (x) + o-cresol (1 - x) mixture at x = 0.4891 and heptane (x) + undecane (1 - x) mixtures at x = 0.0, 0.05, 0.2346, 0.5063, 0.7482, and 0.9511, in the compressed liquid region from (313 to 363) K and from (1 to 25) MPa. Vibrating periods of each fluid or mixture under study were carried out in a commercial vibrating tube densimeter from Anton Paar. Then, their corresponding densities were obtained by relating density and vibrating periods of water and nitrogen or water and R134a as reference fluids with the vibrating period of the concerning fluids. Uncertainties for the measured properties are estimated to be ρ ± 0.2 kg·m^-3, p ± 0.008 MPa, T ± 0.02 K, and x ± 0.0005. Experimental densities were represented within the experimental uncertainty using an empirical equation of six parameters. Thermodynamic-derived properties were also computed from this equation. Excess molar volumes for the binary mixtures of cresols and linear alkanes are negative. Extrapolated densities for the pure components and mixtures at atmospheric pressure are in agreement with the literature data.