Ammonium Sulfate

Ammonium sulfate (NH₄)₂SO₄ is prepared commercially from the ammoniacal liquor of gas-works and is purified by recrystallization. It forms large rhombic prisms, has a somewhat saline taste and is easily soluble in water. The aqueous solution on boiling loses some ammonia and forms an acid sulfate. It is used largely as an artificial manure, and also for the preparation of other ammonium salts.