Fred, The Auto ionization reaction in water:2 H2O ---> ( H3O +) + OH - requires a free energy of 335,000 joules per mole or about 3.4 eV per H3O + formed.
Hmmm....3.4 eV .... the signature of ZPE, it would seem.....kinda like the smile of the Cosmic-Cheshire-Cat... eh, Lewis?
