THE ION HYDRATION SHELL - ELECTROSTATIC AND THERMODYNAMIC APPROACH

Infinitely dilute aqueous ionic solutions are considered. The relative change in water density as a function of the distance from the ion center is calculated in terms of classical thermodynamics and electrostatics. This function attains a maximum at a distance equal to the reduced radius of the first hydration shell of the Li+ ion. The results are consistent with the well-known strong hydration of Li+ ion as compared with the weak hydration of other alkali-metal ions. © 1990 American Chemical Society.