is a polyatomic ion
. 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
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