ferrous sulfate,dried

Iron(II) sulfate

Iron(II) sulfate or ferrous sulfate (British English: sulphate instead of sulfate) denotes a range of salts of iron with the sulfate ion with the formula FeSO4·xH2O. The blue-green heptahydrate (hydrate with 7 molecules of water) is the most common form of this material. The hydrated form is used medically to treat or prevent iron deficiency, and also for industrial applications. Known since ancient times as copperas and as green vitriol (vitriol is an archaic name for hydrated sulfate minerals). All the iron(II) sulfates dissolve in water to give the same aquo complex [Fe(H2O)6]2+, which has octahedral molecular geometry and is paramagnetic. The name copperas dates from times when the copper(II) sulfate was known as blue copperas, and iron(II) and zinc sulfate were known respectively as green and white copperas. It is on the World Health Organization's List of Essential Medicines. As of 2023, it was the 89th most commonly prescribed medication in the United States, with more than 7,000,000 prescriptions.