Bicarbonate

Bicarbonate is a polyatomic ion whose formula is HCO₃^-. It is the intermediate form in the deprotonation of carbonic acid: removing the first proton from carbonic acid forms bicarbonate; removing the second proton leads to the carbonate ion.

The salts which contain the bicarbonate ion are also known as bicarbonates, such as sodium bicarbonate (baking soda) NaHCO₃. Bicarbonates, when exposed to an acid such as acetic acid of vinegar release carbon dioxide. This is used to cause breads to rise in cooking, and in toy rockets.

The bicarbonate/carbonate ionic system is also a buffer in blood.

See also: carbon dioxide, carbonic acid, carbonate