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Sodium bicarbonate



Name Sodium hydrogen carbonate
Chemical formula NaHCO3
Appearance White solid


Formula weight 84.0 amu
Melting point Decomposes at 543 K (270 °C)
Density 2.2 ×103 kg/m3
Crystal structure ?
Solubility 10.3 g in 100g water


ΔfH0solid -951 kJ/mol
S0solid 102 J/mol·K


Ingestion Safe except in very large quantities.
Inhalation May cause irritation.
Skin May cause irritation.
Eyes May cause pain and redness
More info Hazardous Chemical Database
SI units were used where possible. Unless otherwise stated, standard conditions were used.

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Sodium bicarbonate (NaHCO3), or sodium hydrogen carbonate, also known as baking soda, is a soluble white anhydrous or crystalline compound, with a slight alkaline taste resembling that of sodium carbonate. It is found in many mineral springs and also produced artificially.

It is also used as an antacid to treat acid indigestion and heartburn. The anhydrous form is also used to absorb moisture and odours—a box can be left in the refrigerator for this purpose.

Sodium bicarbonate, when exposed to a moderately strong acid, releases carbon dioxide:

It is used in combination with acidic compounds as a leavening agent in baking: some forms of baking powder contain sodium bicarbonate. Formerly, it was used as a source of carbon dioxide for soda water.

See also: baking powder, sodium carbonate, list of minerals