Acid Dissociation of Carbonic Acid and Bicarbonate

Definition

The two successive proton-releasing steps where carbonic acid donates a hydrogen to form bicarbonate, and bicarbonate donates another hydrogen to form carbonate.

H2CO3 dissociates to H+ plus HCO3-, and HCO3- dissociates to H+ plus CO3 2-. Each step generates hydrogen ions, and because the reactions are reversible, hydrogen ions are also the reactants that push the chain back toward CO2. This makes hydrogen, and hydroxide by extension, fundamental determinants of where the equilibrium sits.

Related concepts

Carbonate Equilibrium · pH (Lever) · Dissociation Constants and Temperature

---

Part of The Blueprint of Water · 🧪 chemistry