Manganese(II) nitrate Manganese(II) nitrate Manganese(II) nitrate are the inorganic compounds with formula Mn(NO)(HO). Each formula unit is composed of one Mn cation and two NO anions and varying amounts of water. Most common is the tetrahydrate Mn(NO)·4HO, but mono- and hexahydrates are also known as well as the anhydrous compound. Some of these compounds are useful precursors to the oxides of manganese. Manganese(II) nitrate is prepared by dissolving manganese(II) oxide in nitric acid: It can also be prepared from manganese dioxide and nitrogen dioxide: On heating to 300 °C, aqueous solutions of manganese(II) nitrate thermally decompose to form MnO and NO. Manganese(II)
Manganese to be manganese dioxide) contained a new element, but they were unable to isolate it. Johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, which he did by reducing the dioxide with carbon. Manganese phosphating is used for rust and corrosion prevention on steel. Ionized manganese is used industrially as pigments of various colors, which depend on the oxidation state of the ions. The permanganates of alkali and alkaline earth metals are powerful oxidizers. Manganese dioxide is used as the cathode (electron acceptor) material in zinc-carbon and alkaline batteries. In biology, manganese(II) ions