Names | |
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IUPAC name
manganese(II) dimanganese(III) oxide
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Other names
Manganese tetroxide; Manganese oxide, Manganomanganic oxide, Trimanganese tetraoxide, Trimanganese tetroxide[1]
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Identifiers | |
3D model (JSmol)
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ECHA InfoCard | 100.013.879 |
PubChem CID
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RTECS number |
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
Mn3O4 MnO·Mn2O3 | |
Molar mass | 228.812 g/mol |
Appearance | brownish-black powder[1] |
Density | 4.86 g/cm3 |
Melting point | 1,567 °C (2,853 °F; 1,840 K) |
Boiling point | 2,847 °C (5,157 °F; 3,120 K) |
insoluble | |
Solubility | soluble in HCl |
+12,400·10−6 cm3/mol | |
Structure | |
Spinel (tetragonal), tI28 | |
I41/amd, No. 141 | |
Hazards | |
NIOSH (US health exposure limits): | |
PEL (Permissible)
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C 5 mg/m3[1] |
REL (Recommended)
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None established[1] |
IDLH (Immediate danger)
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N.D.[1] |
Thermochemistry | |
Std molar
entropy (S⦵298) |
149 J·mol−1·K−1[2] |
Std enthalpy of
formation (ΔfH⦵298) |
−1387 kJ·mol−1[2] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Manganese(II,III) oxide is the chemical compound with formula Mn3O4. Manganese is present in two oxidation states +2 and +3 and the formula is sometimes written as MnO·Mn2O3. Mn3O4 is found in nature as the mineral hausmannite.
Mn3O4 formed when any manganese oxide is heated in air above 1000 °C.[3] Considerable research has centred on producing nanocrystalline Mn3O4 and various syntheses that involve oxidation of MnII or reduction of MnVI.[4][5][6]
Mn3O4 has been found to act as a catalyst for a range of reactions e.g. the oxidation of methane and carbon monoxide;[7][8] the decomposition of NO,[9] the reduction of nitrobenzene[10] and the catalytic combustion of organic compounds.[11]
Mn3O4 has the spinel structure, where the oxide ions are cubic close packed and the MnII occupy tetrahedral sites and the MnIII octahedral sites.[3] The structure is distorted due to the Jahn–Teller effect.[3] At room temperature Mn3O4 is paramagnetic, below 41-43 K, it is ferrimagnetic[12] although this has been reported as reducing in nanocrystalline samples to around 39 K.[13]
Mn3O4 is sometimes used as a starting material in the production of soft ferrites e.g. manganese zinc ferrite,[14] and lithium manganese oxide, used in lithium batteries.[15]
Manganese tetroxide can also be used as a weighting agent while drilling reservoir sections in oil and gas wells.[citation needed]