A colourless or white crystalline solid, (NH4)2CO3, usually encountered as the monohydrate. It is very soluble in cold water. The compound decomposes slowly to give ammonia, water, and carbon dioxide. Commercial ‘ammonium carbonate’ is a double salt of ammonium hydrogencarbonate and ammonium aminomethanoate (carbamate), NH4HCO3.NH2COONH4. This material is manufactured by heating a mixture of ammonium chloride and calcium carbonate and recovering the product as a sublimed solid. It readily releases ammonia and is the basis of sal volatile. It is also used in dyeing and wool preparation and in baking powders.