What is the Difference Between Ferric and Ferrous Sulphate?

The key difference between ferric and ferrous sulphate lies in the oxidation state of the iron atoms in their chemical structures. Both ferric and ferrous sulphate are ionic compounds containing cations (iron in different oxidation states) and anions (sulphate).

• Ferric Sulphate: This compound has iron in the +3 oxidation state, with the chemical formula Fe2(SO4)3. The most common hydrated form of ferric sulphate is the pentahydrated form, which appears as yellowish-grey crystals. It is often used in dyeing as a mordant, as a coagulant for industrial wastes, and in the processing of aluminum and steel.
• Ferrous Sulphate: This compound has iron in the +2 oxidation state, with the chemical formula FeSO4. The most common hydrated form of ferrous sulphate is the heptahydrate form. Ferrous sulphate is typically produced via oxidation of pyrite.

Both ferric and ferrous sulphate are used in various applications, such as coagulants for water treatment, dyeing, and industrial processes. However, the choice between the two compounds may depend on factors such as the desired oxidation state, purity requirements, and the specific application.

Comparative Table: Ferric vs Ferrous Sulphate

Here is a table comparing the differences between ferric and ferrous sulphate:

Ferric sulphate has iron in the +3 oxidation state, while ferrous sulphate has iron in the +2 oxidation state. Ferric sulphate is a sulphate of iron with the chemical formula Fe2(SO4)3, and its most common hydrated form is the pentahydrate. Ferrous sulphate, on the other hand, has the chemical formula FeSO4 and is commonly found in the heptahydrate form. Ferric sulphate appears as yellowish-grey crystals, whereas ferrous sulphate forms pale green crystals.