Manganese(II,III) oxide a weighting agent while drilling reservoir sections in oil and gas wells. 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
CB military symbol by the United States – signifying crude mustard. In the Second World War the purity of mustard gas was improved through distillation, and this purified chemical warfare agent was designated HD. When it was mixed with a thickener (Agent VV), it was given the symbol HV. Today mustard gas is indicated by the single capital letter H, but HD is still in common use. Military symbols can also reflect the name of where a chemical agent is manufactured. For example, chloropicrin has the symbol PS, which was derived from the British town in which it was manufactured during the First