Heptahydrate

Iron(II) sulfate (Iron(II) sulphate) or ferrous sulfate (ferrous sulphate) is the chemical compound with the formula (FeSO4), known since ancient times as copperas. It is most commonly encountered as the blue-green heptahydrate.

It has molecular formula Na2HAsO4 7H2O.

Zinc sulfate (ZnSO4) is a colorless crystalline, water-soluble chemical compound. The hydrated form, ZnSO4·7H2O, the mineral goslarite, was historically known as "white vitriol" and can be prepared by reacting zinc with aqueous sulfuric acid. It may also be prepared by adding solid zinc to a copper(II) sulfate solution.