The chemical formula of ammonium sulphate is _________.

The chemical formula of ammonium sulphate is (NH4)2SO4. Ammonium sulphate is an inorganic salt formed by the combination of the ammonium ion (NH4+) and the sulphate ion (SO4^2-). According to the criss-cross method of writing formulas, the valency of the ammonium ion (1) is implied for the sulphate group, while the valency of the sulphate ion (2) becomes the subscript for the ammonium group, giving the resulting compound as electrically neutral, containing two ammonium polyatomic ions for every one sulphate ion.