Abstract
It is shown that a very simple semiempirical equation represents quite accurately the thermodynamic properties of aqueous sodium chloride from 373 to 823 K. The equation comprises one Margules term and a Debye—Hückel term. Just the one Margules parameter is freely adjustable because the Debye—Hückel parameter is determined by the properties of water. The equation is valid from the saturation composition down to infinite dilution for solvent density above 0.75 g·cm-3 but at lower density only above a solute mole fraction of about 0.1 on an ionized basis. Both solute and solvent activity coefficients are fitted from the lowest pressure of solution existence up to 1 kilobar (1 bar = 100 kPA). Derivation of enthalpy and other related functions is discussed.
Keywords: electrolytes, activity coefficients, Gibbs energy, enthalpy
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Selected References
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- Pitzer K. S. Dielectric constant of water at very high temperature and pressure. Proc Natl Acad Sci U S A. 1983 Jul;80(14):4575–4576. doi: 10.1073/pnas.80.14.4575. [DOI] [PMC free article] [PubMed] [Google Scholar]