Saturated liquid densities of polar and nonpolar pure substances

Abstract

Experimental information available in the literature for the density behavior of the saturated liquid state of 46 nonpolar and polar substances has been modeled according to the expression, /rho/ /sub R/ = 1 + ..cap alpha.. (1 - T /sub R/ ) /sup m/ + ..beta..(1 - T /sub R/ ) /sup n/ , in which /rho/ /sub R/ is the ratio of the density at reduced temperature T /sub R/ to the critical density. This relationship has been found to apply over the complete range between the triple point and the critical point. Exponent m is a universal constant (m = 3/8). The critical constants and normal boiling points are needed to establish ..cap alpha.., ..beta.., an n for nonpolar substances. For polar substances, the dipole moment is also required. Saturated liquid densities calculated with correlated values of ..cap alpha.., ..beta.., and n have been compared with corresponding experimental measurements to yield an overall average deviation of 0.83% (4284 points) for the 46 substances used in this development This generalized treatment has been applied to 16 additional substances to yield for them an average deviation of 1.14% (669 points).