Skip to main content Skip to Search Box

Definition: sodium bicarbonate from Philip's Encyclopedia

(sodium hydrogen carbonate, NaHCO3, popularly known as bicarbonate of soda) White, crystalline salt that decomposes in acid or on heating to release carbon dioxide gas. It has a slightly alkaline reaction and is an ingredient of indigestion medicines.


Summary Article: sodium bicarbonate
from The Columbia Encyclopedia

or sodium hydrogen carbonate, chemical compound, NaHCO3, a white crystalline or granular powder, commonly known as bicarbonate of soda or baking soda. It is soluble in water and very slightly soluble in alcohol. It evolves carbon dioxide gas when heated above about 50 degrees Celsius, a property made use of in baking powder, of which it is a component. It is also decomposed by most acids; the acid is neutralized and carbon dioxide is given off. The major use of sodium bicarbonate is in foods, e.g., baked goods. It is used in effervescent "salts" and is sometimes used medically to correct excess stomach acidity. It is also used in several kinds of fire extinguishers. Although it is an intermediate product in the Solvay process for making sodium carbonate, it is more economical to prepare it from purified sodium carbonate than to purify the intermediate. Because the bicarbonate is less soluble than the carbonate, carbon dioxide gas is bubbled into a saturated solution of pure carbonate, and the bicarbonate precipitates out to be collected and dried.

The Columbia Encyclopedia, © Columbia University Press 2017

Related Articles


Full text Article sodium bicarbonate
The Royal Society of Medicine: Medicines

Sodium bicarbonate is an antacid and is used for the rapid relief of indigestion. It is a constituent of many proprietary preparations that...

Full text Article sodium bicarbonate
Academic Press Dictionary of Science and Technology

NaHCO 3 , a white powder or crystalline lumps; loses carbon dioxide on heating to 270°C and decomposes slowly in moist air; soluble in...

Full text Article sodium bicarbonate (sodium hydrogen carbonate or bicarbonate of soda; NaHCO3)
The Macmillan Encyclopedia

The white soluble powder that is a constituent of baking powder and is used to make fizzy drinks and as an antacid in medicine. It...

See more from Credo