Densities and derived thermodynamic properties for the (n-heptane + n-octane), (n-heptane + ethanol) and (n-octane + ethanol) systems at high pressures

•Densities of n-heptane, n-octane, ethanol and their mixtures at high pressures.•The high pressure density modeling using the modified Tait equation.•Calculation of the isobaric thermal expansion coefficient and the isothermal compressibility.•Positive VE of n-heptane + ethanol and n-octane + ethanol mixtures.

This work reports densities for the pure n-heptane, n-octane and ethanol at temperatures from (288.15 to 413.15) K and at pressures up to 60 MPa. The same properties were determined for the binary mixtures n-heptane + n-octane, n-heptane + ethanol and n-octane + ethanol over the temperature range (293.15–373.15) K and at pressures ranging from (0.1 to 40) MPa. Highly precise densimeter DMA HP was used for density measurements. Experimental values of densities were fitted by the modified Tammann–Tait equation. Additionally, derived volumetric properties, e.g. excess molar volumes, isothermal compressibilities and isobaric thermal expansion coefficients were calculated. The effect of pressure and temperature on the measured and derived properties was discussed.