Give chemical formula of the following:

Green vitriol

About Green vitriol:

• It is a hydrated salt as it contains water of crystals.

Uses:

• It is used medically to treat iron deficiency.

Chemical formula:

$\underset{\mathrm{Iron}\left(\mathrm{III}\right)\mathrm{sulphate}\mathrm{heptahydrate}}{{\mathrm{FeSO}}_4.7{\mathrm{H}}_2\mathrm{O}}$