Manganese(II) oxide
| Manganese(II) oxide | |
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Manganese(II) oxide |
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Other names
Manganous oxide |
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| Identifiers | |
| CAS number | 1344-43-0  |
| PubChem | 14940 |
| RTECS number | OP0900000 |
| Properties | |
| Molecular formula | MnO |
| Molar mass | 70.9374 g/mol |
| Appearance | green crystalline |
| Density | 5.37 g/cm3 (23 °C) |
| Melting point |
1945 °C |
| Solubility in water | insoluble |
| Refractive index (nD) | 2.16 |
| Structure | |
| Crystal structure | Halite (cubic), cF8 |
| Space group | Fm3m, No. 225 |
| Coordination geometry |
Octahedral (Mn2+); octahedral (O2–) |
| Hazards | |
| EU Index | Not listed |
| Flash point | Non-flammable |
| Related compounds | |
| Other anions | Manganese difluoride Manganese(II) sulfide |
| Other cations | Iron(II) oxide |
| Related manganese oxides | Manganese(II,III) oxide Manganese(III) oxide Manganese dioxide Manganese heptoxide |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Manganese(II) oxide is the inorganic compound with formula MnO.[1] MnO is a basic oxide that is insoluble in water but dissolves in acids, forming manganese(II) salts.[2]
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[edit] Preparation and occurrence
MnO can be prepared by the reduction of any higher oxide with hydrogen[2] e.g.:
- MnO2 + H2 → MnO + H2O
Commercially it is prepared by reduction of MnO2 with hydrogen, carbon monoxide or methane:[1]
- MnO2 + CO → MnO + CO2
MnO can also be prepared by heating MnCO3:[3]
- MnCO3 → MnO + CO2
This calcining process is conducted anaerobically to prevent formation of Mn2O3. MnO occurs in nature as the rare mineral manganosite.
[edit] Structure and properties
MnO has the NaCl, rock salt structure, where cations and anions are both octahedrally coordinated.[2] The composition of MnO can vary from MnO to MnO1.045.[2]
Below 118 K MnO is antiferromagnetic.[2] MnO has the distinction of being one of the first compounds[4] to have its magnetic structure determined by neutron diffraction in 1951.[5]. This study showed that the Mn2+ ions form a face centered cubic magnetic sub-lattice where there are ferromagnetically coupled sheets which are anti-parallel with adjacent sheets.
[edit] Applications
Together with manganese sulfate, MnO is a component of fertilizer and feed additives. Many thousands of tons are consumed annually for this purpose.[1]
[edit] References
- ^ a b c Arno H. Reidies "Manganese Compounds" Ullmann's Encyclopedia of Chemical Technology 2007; Wiley-VCH, Weinheim. doi:10.1002/14356007.a16_123
- ^ a b c d e Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. ISBN 0080379419.
- ^ W.H. McCarroll (1994) Oxides- solid sate chemistry, Encyclopedia of Inorganic chemistry Ed. R. Bruce King, John Wiley & Sons ISBN 0-471-93620-0
- ^ J.E Greedon, (1994), Magnetic oxides in Encyclopedia of Inorganic chemistry Ed. R. Bruce King, John Wiley & Sons ISBN 0-471-93620-0
- ^ Neutron Diffraction by Paramagnetic and Antiferromagnetic Substances C. G. Shull, W. A. Strauser, and E. O. Wollan, Phys. Rev. 83, 333 - 345 (1951), doi:10.1103/PhysRev.83.333
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