508. Ammonium Carbonate

Nomenclature

CAS number: 8000-73-5
Hartshorn salt.

Description and references

A mixture of ammonium bicarbonate and ammonium carbamate, obtained by subliming a mixture of ammonium sulfate and calcium carbonate. Contains 30-34% NH3, about 45% CO2. See USP XVII, p 941. Review: Allen, “Ammonium Carbonate” in Mellor's Vol. VIII, supplement 1, Nitrogen (part 1) 459-468 (1964).

Properties

Colorless, hard, translucent, crystalline masses, white cubes or powder; strong odor of ammonia; sharp taste and alkaline reactions. Decomposes on exposure to air with loss of NH3 and CO2, becoming white and powdery and converting into ammonium bicarbonate. Volatilizes at about 60°. Freely sol in water. Decomposed by hot water. The carbamate portion dissolves in alcohol. Keep tightly closed in a cool place.
Incompat. Acids and acid salts; salts of iron, zinc; alkaloids, alum, calomel, tartar emetic.

Use

In baking powders, for washing and defatting woolens, tanning; as mordant in dyeing; manuf rubber articles, casein glue, casein colors; in fire extinguishers, smelling salts; for separating cacao constituents; as a reagent in analytical chemistry for pH adjustment. Pharmaceutic aid (source of ammonia; alkalinizing agent; buffering agent).