Critical phenomena and thermodynamics of dilute aqueous sodium chloride to 823 K.
Semiempirical equations are developed that represent the behavior of dilute solutions of NaCl in water (steam) in the range 723-823 K where ion pairing is extensive. This supplements the equations given earlier for more concentrated solutions. In this temperature range the system NaCl/H(2)O shows critical behavior with two phases below the critical pressure. The equations for the dilute solutions yield critical behavior. Though the equations for concentrated solutions do not yield critical behavior at the critical pressure, only a very small interpolation function is required to connect smoothly the two equations. The ion-pairing equilibrium constants are reported as well as the Gibbs energies of hydration for both ions and ion pairs.
Department of Chemistry and Lawrence Berkeley Laboratory, University of California, Berkeley, CA 94720.
K S
KS
Pitzer
Y G
YG
Li