Ammonium sulfate, designated by the chemical formula (NH4)2SO4, is a commonly used inorganic salt in various industries due to its multiple beneficial properties. Its name is derived from the ions that constitute it: two ammonium ions and one sulfate ion .

It is colorless monoclinic crystal and is easy to deliquesce. Soluble in water, heated and dehydrated, and the aqueous solution is neutral or weakly acidic.