It is used as a coagulant in water and wastewater treatment in pigments and dyes analytical chemistry for redox titrations and soil remediation for arsenic stabilization.

Its primary purpose is to provide Fe for oxidation reactions coagulation of colloids via charge neutralization and acidic catalysis in industrial processes.

Iron(III) sulfate pentahydrate (Fe(SO)5HO) is a pale yellow to beige crystalline or granular solid hygroscopic and water-soluble consisting of two Fe cations and three sulfate anions with five waters of hydration.