Article Accurate Experimental Values for the Free Energies of Hydration of H+, OH-, and H3O+

Authors

George C. Shields, Bucknell UniversityFollow
Matthew W. Palascak

Publication Date

3-18-2004

Description

Accurate experimental values for the free energies of hydration, or the free energies of solvation, of the H⁺, OH^-, and H₃O⁺ ions are of fundamental importance. By use of the most accurate value for the free energy of solvation of H⁺, the known value for the free energy of solvation of water, and the known values for the gas phase and aqueous phase deprotonation of water, the corresponding experimental free energy of solvation for OH^- is −106.4 ± 0.5 kcal/mol. Similarly, by use of the known values for ΔG_f⁰ for H₃O, H₂O⁺, and OH^-, the known values for ΔG_s for H⁺ and OH^-, and the known value for the aqueous phase autoionization of water, we obtain an experimental free energy of solvation value for H₃O⁺ of −103.4 ± 0.5 kcal/mol. These values are in excellent agreement with the commonly accepted values and with the value for ΔG_s(OH^-) obtained from embedding clusters of OH^-(H₂O)_n in a dielectric continuum.

Journal

Journal of Physical Chemistry

Volume

108

Issue

16

First Page

3692

Last Page

3694

Department

Chemistry

Link to Published Version

http://dx.doi.org/10.1021/jp049914o

Recommended Citation

Shields, George C. and Palascak, Matthew W.. "Article Accurate Experimental Values for the Free Energies of Hydration of H+, OH-, and H3O+." Jounral of Physical Chemistry (2004) : 3692-3694.