HCO3?

HCO3 is the chemical form of bicarbonate.
The bicarbonate ion (hydrogen carbonate) is an anion with the empirical formula HCO3− and a molecular mass of 61.01 daltons; it consists of one central carbon atom surrounded by three oxygen atoms in a trigonal planar arrangement, with a hydrogen atom attached to one of the oxygens. The bicarbonate ion carries a negative one formal charge and is the conjugate base of carbonic acid, H2CO3; it is the conjugate acid of CO32−, the carbonate ion as shown by these equilibrium reactions.

CO32- +2 H2O ⇋ HCO31- + H2O + OH1- ⇋ H2CO3 +2 OH1-

H2CO3 +2 H2O ⇋ HCO31- + H3O1+ + H2O ⇋ CO32- +2 H3O1+

A bicarbonate salt forms when a positively charged ion attaches to the negatively charged oxygen atoms of the ion, forming an ionic compound. Many bicarbonates are soluble in water at standard temperature and pressure, particularly sodium bicarbonate and magnesium bicarbonate; both of these substances contribute to total dissolved solids, a common parameter for assessing water quality.

[edit] Bicarbonate Compounds
Sodium bicarbonate
Potassium bicarbonate
Calcium bicarbonate
Ammonium bicarbonate

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