<unk> (II) sulfate is the chemical compound with the formula <unk> SO4). Also known as<unk> rrous sulphate, or copperas,<unk> (II) sulfate is most commonly encountered as the blue-green heptahydrate. 
In its anhydrous, crystalline state, its standard enthalpy of formation is ΔfH°solid = -928.4 kJ.mol-1 and its standard molar entropy is S°solid = 107.5 J.K-1.mol-1.
Iron
Heme
Copper
Biotin
Thiol
Psyllium
Nickel
Selenium sulfide