ChEBI: Iron(2+) sulfate (anhydrous) is a compound of iron and sulfate in which the ratio of iron(2+) to sulfate ions is 1:1. Various hydrates occur naturally - most commonly the heptahydrate, which loses water to form the tetrahydrate at 57### and the monohydrate at 65###. It has a role as a reducing agent. It is a metal sulfate and an iron molecular entity. It contains an iron(2+).