Iron(II) sulfate

Structure of the hexaaquairon(II) sulfate complex

Iron(II) sulfate, also known as ferrous sulfate, is a chemical compound with the formula FeSO₄. It is commonly encountered as the heptahydrate, FeSO₄·7H₂O, which is a blue-green crystalline solid. This compound is used in various applications, including as a precursor to other iron compounds, in water treatment, and as a nutritional supplement.

Chemical Properties

Iron(II) sulfate is a sulfate salt of iron in the +2 oxidation state. The anhydrous form is a white crystalline solid, while the heptahydrate form is blue-green. The compound is soluble in water, and its solutions are acidic due to hydrolysis.

3D model of iron(II) sulfate heptahydrate

Hydration States

Iron(II) sulfate exists in several hydrated forms, the most common being the heptahydrate. Other hydrates include the monohydrate and tetrahydrate. The heptahydrate loses water upon heating, eventually forming the anhydrous form.

Production

Iron(II) sulfate is produced by treating iron with sulfuric acid, often as a byproduct of the pickling of steel:

Fe + H₂SO₄ → FeSO₄ + H₂

It can also be obtained by the oxidation of pyrite (iron sulfide) or by the reaction of iron with copper(II) sulfate.

Applications

Industrial Uses

Iron(II) sulfate is used in the manufacture of iron(III) oxide pigments, as a reducing agent in the treatment of chromate-containing effluents, and in the production of iron(III) sulfate.

Sample of iron(II) sulfate heptahydrate

Agriculture

In agriculture, iron(II) sulfate is used as a soil amendment for lowering the pH of a high alkaline soil so that plants can access the soil's nutrients. It is also used to treat iron chlorosis, a condition in which leaves produce insufficient chlorophyll.

Medical Uses

Iron(II) sulfate is used as a dietary supplement to treat iron-deficiency anemia. It is available in various forms, including tablets and liquid solutions.

Safety

Iron(II) sulfate is generally considered safe when used as directed. However, it can be toxic in large amounts, particularly to children. It should be stored out of reach of children and handled with care to avoid ingestion.

Iron(II) sulfate crystals

Related Compounds

• Iron(III) sulfate
• Copper(II) sulfate
• Zinc sulfate

Related Pages

• Iron
• Sulfate
• Anemia