Manganese(II,III) oxide Manganese(II,III) oxide Manganese(II,III) oxide is the chemical compound with formula MnO. Manganese is present in two oxidation states +2 and +3 and the formula is sometimes written as MnO.MnO. MnO is found in nature as the mineral hausmannite. MnO formed when any manganese oxide is heated in air above 1000 °C. Considerable research has centred on producing nanocrystalline MnO and various syntheses that involve oxidation of Mn or reduction of Mn. MnO has been found to act as a catalyst for a range of reactions e.g. the oxidation of methane and carbon monoxide; the decomposition of NO, the reduction of
Manganese(II) carbonate Manganese(II) carbonate Manganese carbonate is a compound with the chemical formula MnCO. Manganese carbonate occurs naturally as the mineral rhodochrosite but it is typically produced industrially. It is a pale pink, water-insoluble solid. Approximately 20,000 metric tonnes were produced in 2005. MnCO adopts a structure like calcite, consisting of manganese(II) ions in an octahedral coordination geometry. Treatment of aqueous solutions of manganese(II) nitrate with ammonia and carbon dioxide leads to precipitation of this faintly pink solid. The side product, ammonium nitrate is used as fertilizer. The carbonate is insoluble in water but, like most carbonates, hydrolyses upon treatment with acids