Temperature and density effects on the high temperature ionic speciation in dilute Na{sup +}/Cl{sup {minus}} aqueous solutions

Journal Article · Fri Nov 01 04:00:00 EST 1996 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.472756· OSTI ID:389275

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

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1. Department of Chemical Engineering, 419 Dougherty Engineering Building, University of Tennessee, Knoxville, Tennessee 37996-2200 (United States)
2. Chemical and Analytical Science Division, Oak Ridge National Laboratory. Oak Ridge, Tennessee 37831-6110 (United States)

Molecular simulation of dilute NaCl aqueous solutions is performed to study the Na{sup +}/Cl{sup {minus}} ion-pair association and the constant of equilibrium between the solvent separated (shared) and contact ion pairs at high temperature. Using the simple point charge, the Pettitt{endash}Rossky, and the Fumi{endash}Tosi models for the water{endash}water, the ion{endash}water, and the ion{endash}ion interactions, we determine the density dependence of the constants along the {ital T}{sub {ital r}}={ital T}/{ital T}{sub {ital c}}=1.05 isotherm, and the temperature dependence along the {rho}{sub {ital r}}={rho}/{rho}{sub {ital c}}=1.5 isochore. The simulation results for the association constant are then compared with the predictions of two recent correlations based on conductance measurements at high temperature. The outcome of the comparison is interpreted in terms of the microstructural behavior of the solvent around the ions and the realism of its dielectric behavior. {copyright} {ital 1996 American Institute of Physics.}

• Research Organization: Oak Ridge National Laboratory
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 389275
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 20 Vol. 105; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
AQUEOUS SOLUTIONS
COMPUTERIZED SIMULATION
DENSITY
ION PAIRS
MICROSTRUCTURE
SODIUM CHLORIDES
SOLVATION
SOLVENT EFFECTS
TEMPERATURE DEPENDENCE