Hydronium Treatment: H3O+ vs. H+ Equilibrium Constants

[Big-Daddy]

Is it true that the reaction 2 H₂O = H₃O⁺ + OH^- has a different equilibrium constant to that of K_w, H₂O = H⁺ + OH^- ? How can that be?

If we want a decent treatment of an acid-base system using [H₃O⁺] rather than the less accurate [H⁺], what modifications do we have to make to the process used for the simple [H⁺] case?

 

[Yanick]

No modifications necessary, they are treated exactly the same. It's simply a matter of changing the labels because free protons are not thought to exist in solution such that it is more realistic to denote the proton by using the hydronium label.