Note 183 — Chapter VI · CHEMICAL EQUILIBRIUM. THE LAW OF MASS ACTION

Owing to the instability of carbonic acid, which breaks down into carbon dioxide and water (H2CO3 ⇄ H2O + CO2), the carbonic acid is, in turn, in equilibrium with the carbon dioxide. For the sake of simplicity, this relation is not included in the detailed discussion, and wherever the symbols H2CO3 and [H2CO3] are used, they are intended to represent the total carbonic acid, present as such and as carbon dioxide. The detailed discussion of the complication mentioned will be given in connection with the analogous case of ammonium hydroxide and ammonia, and, as will be shown there, with the significance just attached to the symbols, the relations developed in the text are a rigorous expression of the facts.