Liquid densities of n-octane, ethylcyclohexane and their binary mixtures {(x) n-octane) + (1 − x) ethylcyclohexane} at temperatures from (283 to 363) K and pressures up to 60 MPa

In this work, liquid densities of n -octane, ethylcyclohexane and their binary mixtures {( x ) n -octane) + (1 −  x ) ethylcyclohexane} with mole fraction x = (0.200, 0.400, 0.600, 0.800) are reported. The density measurements were performed with a high-pressure vibrating-tube densimeter at temperatures from (283 to 363) K and pressures up to 60 MPa. The combined expanded uncertainties (0.95 level of confidence, k  = 2) are estimated to be 16 mK for temperature, 0.062 MPa for pressure, and up to 0.6 kg/m 3 for density. The experimental densities were correlated using the modified Tait equation. The average absolute percentage deviations of measurement results from the modified Tait equation correlations of n -octane, ethylcyclohexane and their binary mixtures {( x ) n -octane) + (1 −  x ) ethylcyclohexane} are all lower than 0.1%. The isothermal compressibility and isobaric expansivity have also been derived from the experimental densities.