A blue-green monoclinic crystal or particle. Odorless. Weathering in dry air. The surface is oxidized to brown basic ferric sulfate in humid air. It becomes tetrahydrate at 56.6 ℃ and monohydrate at 65 ℃. Soluble in water, almost insoluble in ethanol. Its aqueous solution is oxidized slowly in air when it is cold and faster when it is hot. The addition of alkali or dew can accelerate its oxidation. Relative density (d15) 1.897. Half lethal dose (mouse, oral) 1520 mg / kg. Have irritation. Anhydrous ferrous sulfate is a white powder, which contains crystal water and is light green crystal. The crystal is commonly called "green", and soluble in aqueous solution is light green. Used for chromatographic analysis reagent. Platinum, selenium, nitrite and nitrate were determined by drip analysis. Reductant. Make ferrite. Clean water. Polymerization catalyst Photographic plate making
