[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?

[Mr Lead]

No,it's not true. The equilibrium constant value is the same, It's only a different symbology, both express the same chemical concept. Anyhow H₃O⁺ is the better way, because in aqueous solution H⁺ can't "live" free, "isolated" but is always associated to the relative base H2O.