Ammonium Carbonate (sal volatile; (NH₄)₂CO₃) , molecular mass 96.09 g/mol, density 1.50 g/cm3 , melting point 58 °C .
A white solid that crystallizes as plates or prisms. It is very soluble in water and readily decomposes on heating to ammonia, carbon dioxide, and water. The white solid sold commercially as ammonium carbonate is actually a double salt of both ammonium hydrogencarbonate (NH₄HCO₃) and ammonium aminomethanoate (NH₂CO₂NH₄). This salt is manufactured from ammonium chloride and calcium carbonate. It decomposes on exposure to air into ammonium hydrogencarbonate and ammonia, and it reacts with ammonia to give the true ammonium carbonate. Commercial ammonium carbonate is used in baking powders, smelling salts, and in the dyeing and woolscouring industries.