Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

Densities of binary water+ethanol and ternary water+ethanol+LiNO3 mixtures have been measured over the temperature range from 298 K to 448 K and at pressures up to 40 MPa using the constant-volume piezometer immersed in a precision liquid thermostat. The measurements for water+ethanol mixture were made for four compositions of 0.0168, 0.0368, 0.0855, and 0.1166 mole fraction of ethanol. The measurements for thernary water+ethanol+LiNO3 mixtures were performed in the same temperature and pressure ranges for twelve concentrations. The expanded uncertainty of the density, pressure, temperature, and concentration measurements at the 95 % confidence level with a coverage factor of k = 2 is estimated to be 0.06 %, 0.05 %, 15 mK, and 0.015 %, respectively. The derived volumetric properties such as excess, apparent, and partial molar volumes were calculated using the measured values of density for the binary water+ethanol mixture and for pure water and ethanol. The small and negative values of excess molar volume for the mixtures were found at all experimental temperatures, *Revised Manuscript Click here to view linked References 440 pressures, and over the entire concentration range. The excess molar volume minimum is found at concentration about 0.4 mole fraction of 1-propanol. The concentration minimum of the derived apparent molar volumes near 2 mol kg-1 (dilute mixture) was observed.