Abstract
A critical review on absolute hydration enthalpies of ions derived by various methods is presented. Definitions on absolute and conventional hydration enthalpies are presented. Values based on the TATB extrathermodynamic hypothesis, those from electrochemical methods, those from gas phase thermodynamic measurements on ion-water molecule association, those from computer simulations, and those based on a physical model for hydrated ion clusters, are discussed. Thermochemical studies on tetra-alkylammonium halides carried out by the authors are briefly summarized in relation to the present topic.
