PVT Properties of Water. II. Virial Coefficients in the Range 150°–450°C without Independent Measurement of Vapor Volumes

Abstract

The equation of state of steam has been determined at 25° intervals from 150° to 450°C by measuring the mass of water injected into a high-temperature vessel as a function of pressure. The observations have been analyzed by a new method that does not require an independent volume of the vessel and are reported as the second and third virial coefficients and as empirical equations for them. The standard error of the second virial coefficient, taking account of the effects of experimental scatter and of truncation of the virial equation, which are comparable at 450°C, is 3% at 150° and 1% at 450°C. The Stockmayer potential fits the second virial coefficient fairly well, but predicts the wrong form for the third.

Towards an accurate intermolecular potential for water

“…ASP is the potential described in the text; ASP(S) uses the dispersion function of Szcz,gniak et al instead of the Rijks and Wormer function. a Reference [80] and [81]. b Reference [35].…”

Measurements of the (p, ρ,T) properties and virial coefficients of pure water, methane,n-hexane,n-octane, benzene, and of their aqueous mixtures in the supercritical region

“…--, values calculated from square-well potential. (40) r, Kell et al; (41) (45) w · , Haar et al; (46) w, O'Connell and Prausnitz; (47) (57) +, Griskey and Canjar; (58,59) R, McGlashan and Potter; (22) w, Collings and Laughlin; (69) U, Lee and Edmister; (70) $, Pompe and Spurling. (71) calculated using the two potential functions.…”

The solvation of sodium ions in water clusters: intermolecular potentials for Na+-H2O and H2O-H2O

“…A change in K w of 0.1 au changes B by about 3 cm 3 mol a at 673 K, so the value of K w is determined by the second virial coefficient data to within about 0.05. The agreement with experiment at temperatures of 473 K and above is excellent, but at 423 K the calculated second virial coefficient is not as negative as the experimental value of Kell et al [66]. However, after the current work was completed, the recent results of Eubank et al [67] were discovered.…”

“…The rms percentage fitting error is 3'9 %, which is smaller than the error in the fit to the penetration energy. The parameter K w is fitted to experimental second virial coefficient data [66]. The second virial coefficient of water can be calculated, neglecting quantum corrections, from the integral…”