Oxyacid Carbonic acid and carbonate salts | Britannica
Carbonic acid and carbonate salts. Carbonic acid (H 2 CO 3) is formed in small amounts when its anhydride, carbon dioxide (CO 2), dissolves in water. CO 2 + H 2 O ⇌ H 2 CO 3 The predominant species are simply loosely hydrated CO 2 molecules. Carbonic acid can be considered to be a diprotic acid from which two series of salts can be formed—namely, hydrogen carbonates, containing HCO 3 ...