H3O+/Cl- Association in High-Temperature Aqueous Solutions over a Wide Range of State Conditions. A Direct Comparison between Simulation and Electrical Conductance Experiment

• Published in: The journal of physical chemistry. B Vol. 106; no. 8; pp. 2041 - 2046
• Main Authors: Chialvo, A. A, Ho, P. C, Palmer, D. A, Gruszkiewicz, M. S, Cummings, P. T, Simonson, J. M
• Format: Journal Article
• Language: English
• Published: American Chemical Society 28.02.2002
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/jp013255n

The radial profiles of the potential of mean force for the H3O+···Cl- pair are determined by constraint molecular dynamics of infinitely dilute high-temperature HCl aqueous solutions over a wide range of state conditions. The ion-pair association constant are consequently calculated and compared with those obtained from the most accurate recent electrical conductance experiments [Ho, P. C.; Palmer, D. A.; Gruszkiewicz, M. S. J. Phys. Chem. B 2001, 105, 1260−1266] at corresponding states. Resulting equilibrium constants between contact and solvent-shared ion-pair configurations indicate that more than 97% of configurations are contact ion-pairs. The adequacy of some simple fully electrostatic models to represent ion-pair association behavior in high-temperature aqueous solutions is also discussed.