Revised densities of { xCO 2 + (1 − x)H 2O} with x < 0.014 at supercritical conditions Molar volumes, partial molar volumes of CO 2 at infinite dilution, and excess molar volumes

Abstract

This communication revises the published (Crovetto et al. J. Chem. Thermodynamics 1990, 22, 231) differences in densities between water and dilute {xCO2 + (1 − x)H2O}, with 0.001 < x < 0.014, measured at temperatures from 651.1 K to 725.5 K at (28.0, 33.0, and 38.0) MPa. From the new densities the infinite-dilution partial molar volumes and the excess molar volumes are calculated. The mixtures, although dilute, are very non-ideal because of the proximity of the critical point. The integral of the indirect pair-correlation function Cδ1 2 is a simple function of pure-water density ρ*. The values of Cδ1 2 for CO2, Ar, Xe, and C2H4 at the same ρ* are approximately equal. Krichevskii's A-parameter calculated from the results is now in good agreement with the value calculated from the slope of the critical line.