Solvation in high-temperature electrolyte solutions. II. Some formal results

Journal Article · Fri Jan 01 04:00:00 EST 1999 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.478151· OSTI ID:289234

Chialvo, A A; Cummings, P T ^[1]; Simonson, J M; Mesmer, R E ^[2]

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1. Department of Chemical Engineering, University of Tennessee Knoxville, Tennessee 37996-2200 (United States)
2. Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110 (United States)

Our molecular-based formalism for infinitely dilute supercritical nonelectrolyte solutions is extended to electrolyte solutions by establishing rigorous connections between the microscopic behavior of the solvent around individual ionic species and their macroscopic solvation behavior. The formalism relies on the unambiguous splitting of the mixture{close_quote}s properties into short-ranged (finite) and long-ranged (diverging) contributions, associated with the corresponding solvation and compressibility-driven phenomena, respectively. The salt (solute) and solvent{close_quote}s residual chemical potentials are linked to the change of the local solvent{close_quote}s environment around the infinitely dilute anion and cation, and the salt partial molar properties are interpreted in terms of the individual ion partial molar counterparts without introducing any extra-thermodynamic assumption. This is achieved with the use of Kusalik and Patey{close_quote}s version of the Kirkwood{endash}Buff fluctuation theory of mixtures. Moreover, the salt-and the individual ion-induced effects are connected to the solvent{close_quote}s electrostriction around the ions, and to the coefficients of the Helmholtz free energy expansion for dilute mixtures. The ion-induced effects are also linked to well-defined excess solvation numbers which do not rely on any choice of solvation shell radius. Finally, some theoretical implications concerning the modeling of high-temperature aqueous-electrolytes solutions are discussed. {copyright} {ital 1999 American Institute of Physics.}

• OSTI ID: 289234
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 2 Vol. 110; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
AQUEOUS SOLUTIONS
ELECTROCHEMISTRY
ELECTROLYTES
FREE ENERGY
SOLUTIONS
SOLVATION
THERMODYNAMIC PROPERTIES