The following discussion took place during April 1999.



My recent question with respect to N2 inclusions has been adequately answered, but has me thinking about my own analysis, and the construction of L-V curves and isochores for NaCl solutions. I have been using the data contained in:

Haas, J.L. Jr., Physical Properties of the Coexisting Phases and Thermochemical Properties of the H2O Component in Boiling NaCl Solutions, U.S.G.S. Bulletin 1421-A, 1976,


Potter, R.W. II, Brown, D.L., The Volumetric Properties of Aqueous Sodium Chloride Solutions from Oo to 500 oC at Pressures up to 2000 Bars Based on a Regression of Available Data in the Literature, U.S.G.S. Bulletin 1421-C, 1977

..but these are older publications. Judging from the response generated from my question on N2 inclusions, I assume there is also more recent literature on NaCl solutions. Can anyone help me?

David Boyer

a very good assessment. I'll be diplomatic and abstain from commenting on the 'accuracy' of the work you cited but if you're only using them to construct isochoric P-T paths for fluid inclusions those works are probably as good as any. If you want accurate density data for aqueous NaCl (or other chloride) solutions you should go for:

Gates, JA and Wood, RH (1989) Density and apparent molar volume of aqueous CaCl2. J. Chem. Eng. Data 34, 53.

Majer, V, Gates, JA, Inglese, A, and Wood, RH (1988) Volumetric properties of aqueous NaCl solutions from 0.0025 to 5.0 molÔkg-1, 323 to 600 K, and 0.1 to 40 MPa. J. Chem. Thermo. 20, 949.

Majer, V, Hui, L, Crovetto, R, and Wood, RH (1991) Volumetric properties of aqueous 1-1 electrolyte solutions near and above the critical temperature of water I. Densities and apparent molar volumes of NaCl(aq) from 0.0025 to 3.1 molÔkg-1, 604.4 to 725.5 K, and 18.5 to 38.0 MPa. J. Chem. Thermo. 23, 213.

Oakes, CS, Simonson, JM and Bodnar, RJ (1995) Apparent molar volumes of aqueous calcium chloride to 250C, 400 bars, and molalities of 0.242 to 6.150. J. Soln. Chem 24, 897.

Simonson, JM, Oakes, CS, and Bodnar, RJ (1994) Densities of NaCl(aq) to the temperature 523 K at pressures to 40 MPa measured with a new vibrating-tube densitometer. J. Chem. Thermo. 26, 345.

those refs, refs in 'em, and subsequent citations to them should float your boat. Vladimir Majer (he's in France, Claremont-Ferrand?) has published additional (some very recent) high temperature stuff for a number of aqueous systems but I don't have the refs handy. Additional density (and heat capacity) data also come out of Bob Wood's group at U. Delaware (Chemistry Dept). Don Archer (NIST, Gaithersburg) probably has the best comprehensive model for aqueous NaCl around (a Pitzer model). I'm not sure if his paper has tables but failing that there's also the work of Rogers and Pitzer (about 1984). Both models are in J. Phys. Chem Ref Data. Archer's model is good to about 300 C, 1 kb, and about 5.5 molal (I think).

Archer, DG (1992) Thermodynamic properties of the NaCl+H2O system. II. Thermodynamic properties of NaCl(aq), NaClÔ2H2O(cr), and phase equilibria. J. Phys. Chem. Ref. Data 21, 793.

For temps above 300 C I'd use one of Andrzej Anderko's models:

Anderko, A and Pitzer, KS (1993) Equation of state representation of phase equilibria and volumetric properties of the system NaCl-H2O above 573 K: Equation of state representation. Geochem. Cosmo. Acta 57, 1657.

Anderko, A and Pitzer, KS (1993) Phase equilibria and volumetric properties of the systems KCl-H2O and NaCl-KCl-H2O above 573 K: Equation of state representation. Gecochem. Cosmo. Acta 57, 4885.

Jiang, S and Pitzer, KS (1996) Phase equilibria and volumetric properties of aqueous CaCl2 by an equation of state. AIChE J. 42, 585. (most of the volumetric data and some of the phase equilibria data used to develop this model was obtained by myself and Mike Simonson. if my memory is correct that fact is not properly acknowledged in this paper.)

one more ref to CaCl2(aq) model (i'd be remiss if I didnt mention it and 'cause Howard is a good guy):

H. Holmes et al. (1994) CaCl2(aq) at elevated temperatures. Enthalpies of dilution, isopiestic molalities, and thermodynamic properties. J. Chem Thermo. 26, 271. (also see v. 29, 1363.)

and while I'm at it:

Hovey, JK, Pitzer, KS, Tanger, JC IV, Bischoff, JL, and Rosenbauer, RJ (1990) Vapor-liquid phase equilibria of potassium chloride-water mixtures: Equation-of-State representation for KCl-H2O and NaCl-H2O. J. Phys. Chem. 94,

Bischoff, JL and Rosenbauer, RJ (1986) The system NaCl-H2O: Relations of vapor-liquid near the critical temperature of water and of vapor-liquid-halite from 380 to 500C. Geochim. Cosmo. Acta 50, 1437.

Bischoff, JL and Rosenbauer, RJ (1988) Liquid-vapor relations in the critical region of the system NaCl-H2O from 380 to 415C: A refined determination of the critical point and two-phase boundary of seawater. Geochim. Cosmo. Acta 52, 2121.

Bischoff, JL and Pitzer, KS (1989) Liquid-vapor relations for the system NaCl-H2O: Summary of athe P-T-x surface from 300 to 500C. Am. J. Sci. 289, 217.

Bischoff, JL, Rosenbauer, RJ, and Fournier, RO (1996) The generation of HCl in the system CaCl2-H2O: Vapor-liquid relations from 380-500C. Geochim. et Cosmo. Acta. 60, 7.

one more ref for aq electrolyte vols (and other properties) which I forgot about at the time I first replied but might be useful to folks:

Wang, P. et al. (1998) Thermodynamic properties of aqueous magnesium chloride solutions from 250 to 600 K and 100 MPa. J. Phys. Chem. Ref. Data 27, 971-991. Has tables for apparent molar volumes at 373, 473, 573, and 623 K and 20, 100, 200, and 300 bars and 0.001 to 3.0 molal.

Charlie Oakes

To David Boyer and Charlie Oakes:

Charlie listed several excellent references for the densities and thermo properties of H2O-NaCl solutions. However, the best reference in terms of fluid inclusion studies is the paper by Bodnar and Vityk:

Bodnar, R. J. and M. O. Vityk (1994) Interpretation of microthermometric data for H2O-NaCl fluid inclusions. in Fluid Inclusions in Minerals, Methods and Applications, B. De Vivo and M. L. Frezzotti, eds., pub. by Virginia Tech, Blacksburg, VA, p. 117-130.

This paper gives equations and tables for determining the salinity from either ice melting or halite dissolution temperatures, equations and graphs for the liquidi, and equations for determining the slopes of the isochores (iso-Th lines) for compositions ranging from 0-40 wt.%, and up to 6 kbars and 800C. Most importantly, the equations are designed to be used by fluid inclusionists, so the input data are temperatures of phase changes that are easily measured during microthermometry.

Cheers, Bob Bodnar

Dr. Robert J. Bodnar
C.C. Garvin Professor of Geochemistry
Department of Geological Sciences
4044 Derring Hall
Virginia Tech
Blacksburg, VA 24061-0420

Tel: (540) 231-7455 (O)
(540) 953-2448 (H)
Fax: (540) 231-3386


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