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It may refer more specifically to the following manganese minerals: Birnessite, (Na,Ca) 0.5 (Mn IV,Mn III) 2 O 4 · 1.5 H 2 O; Buserite, MnO 2 ·nH 2 O; Hausmannite, Mn II Mn III 2 O 4; Manganite, Mn III O(OH)
Manganese(II,III) oxide is the chemical compound with formula Mn 3 O 4. Manganese is present in two oxidation states +2 and +3 and the formula is sometimes written as MnO·Mn 2 O 3. Mn 3 O 4 is found in nature as the mineral hausmannite.
MnCO 3 → MnO + CO 2. This calcining process is conducted anaerobically, lest Mn 2 O 3 form. An alternative route, most interest for demonstration purposes, is the "oxalate method". Also applicable to the synthesis of ferrous oxide and stannous oxide, it entails heating in an oxygen-free atmosphere (often CO 2), hydrated manganese(II) oxalate: [9]
Heating MnO 2 in air at below 800 °C produces α-Mn 2 O 3 (higher temperatures produce Mn 3 O 4). [5] γ-Mn 2 O 3 can be produced by oxidation followed by dehydration of manganese(II) hydroxide. [5] Many preparations of nano-crystalline Mn 2 O 3 have been reported, for example syntheses involving oxidation of Mn II salts or reduction of MnO 2 ...
All of these salts dissolve in water to give faintly pink solutions of the aquo complex [Mn(H 2 O) 6] 2+. The structure of MnSO 4 ·H 2 O has been determined by X-ray crystallography (see figure). The tetrahydrate also features Mn(II) in an O 6 coordination sphere provided by bridging two sulfate anions and four aquo ligands. [3]
The most stable are 53 Mn with a half-life of 3.7 million years, 54 Mn with a half-life of 312.2 days, and 52 Mn with a half-life of 5.591 days. All of the remaining radioactive isotopes have half-lives of less than three hours, and the majority of less than one minute.
The crystal structure of manganese(II) sulfide is similar to that of sodium chloride.. The pink color of MnS likely results from poor coupling between the lowest energy unoccupied Mn orbitals, resulting in discrete states rather than a delocalized band.
MMT has been used in Canadian gasoline since 1976 (and in numerous other countries for many years) at a concentration up to 8.3 mg Mn/L (though the importation and interprovincial trade of gasoline containing MMT was restricted briefly during the period 1997–1998) [3] [4] and was introduced into Australia in 2000. It has been sold under the ...