Manganese(II) sulfate usually refers to the inorganic compound with the formula MnSO4·H2O. This pale pink deliquescent solid is a commercially significant manganese(II) salt. Approximately 260,000 tonnes of manganese(II) sulfate were produced worldwide in 2005. It is the precursor to manganese metal and many other chemical compounds. Manganese-deficient soil is remediated with this salt.Like many metal sulfates, manganese sulfate forms a variety of hydrates: monohydrate, tetrahydrate, pentahydrate, and heptahydrate. All of these salts dissolve in water to give faintly pink solutions of the aquo complex [Mn(H2O)6]2+. The structure of MnSO4·H2O has been determined by X-ray crystallography (see figure). The tetrahydrate also features Mn(II) in an O6 coordination sphere provided by bridging two sulfate anions and four aquo ligands.Manganese(II) sulfate monohydrate is primarily used as a fertilizer and livestock supplement in manganese-deficient soils. It also finds applications in the production of ceramics, varnishes, and glazes, and as a colorant in dyes. Additionally, it’s used in the manufacturing of dry-cell batteries and as a precursor for other manganese compounds.