Manganese
Manganese General
| Name:Manganese | Symbol:Mn |
| Type:Transition Metal | Atomic weight:54.9380 |
| Density @ 293 K: 7.43 g/cm3 | Atomic volume: 7.4 cm3/mol |
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Discovered:
Manganese compounds have been used since ancient times. Manganese was first isolated by Johan G Gahn in 1774 by reduction of the dioxide with carbon. The element name comes from the Latin word 'magnes', meaning magnet. |
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Manganese States
| State (s, l, g):solid | |
| Melting point:1523 K (1250 °C) | Boiling point:2333 K (2060 °C) |
Manganese Energies
| Specific heat capacity:0.48 J g-1 K-1 | Heat of atomization: 283 kJ mol-1 |
| Heat of fusion:12.91 kJ mol-1 | Heat of vaporization :219.74 kJ mol-1 |
| 1st ionization energy:717.4 kJ mol-1 | 2nd ionization energy: 1509 kJ mol-1 |
| 3rd ionization energy:3248.3 kJ mol-1 | Electron affinity:kJ mol-1 |
Manganese Oxidation & Electrons
| Shells:2,8,13,2 | Electron configuration:[Ar] 3d5 4s2 |
| Minimum oxidation number:-3 | Maximum oxidation number:7 |
| Min. common oxidation no.:0 | Max. common oxidation no.:2 |
| Electronegativity (Pauling Scale):1.55 | Polarizability volume:9.4 Å3 |
Manganese Appearance & Characteristics
| Structure:special: complex (cubic) | Color: gray-white |
| Hardness:6.0 mohs | |
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Harmful effects:
Exposure to manganese in excess is considered to be toxic. |
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Characteristics:
Manganese is a gray-white, hard, brittle, metal that can take a high polish. The metal tarnishes on exposure to air and, when heated, oxidizes to manganese(II, III) oxide (Mn3O4). Uses: Manganese is used extensively to produce a variety of important alloys and to desulfurize and deoxidize steel. The metal is also used in dry cell batteries. Manganese dioxide is used as a black-brown pigment in paint. Organo-manganese compounds can be added to gasoline to increase its octane rating and reduce engine knock. Manganese is an essential trace element for living creatures. |
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Manganese Reactions
| Reaction with air:mild, w/ht ⇒ Mn3O4, Mn3N2 | Reaction with 6 M HCl:mild, ⇒ H2, MnCl2 |
| Reaction with 15 M HNO3:mild, ⇒ Mn(NO3)2, Nox | Reaction with 6 M NaOH: |
Manganese Compounds
| Oxide(s):MnO, Mn3O4, Mn2O3, Mn2O7 | Chloride(s): MnCl2 |
| Hydride(s):None |
Manganese Radius
| Atomic radius:140 pm | Ionic radius (1+ ion):pm |
| Ionic radius (2+ ion):89 pm | Ionic radius (3+ ion):75.3 pm |
| Ionic radius (2- ion):pm | Ionic radius (1- ion):pm |
Manganese Conductivity
| Thermal conductivity:7.81 W m-1 K-1 | Electrical conductivity:0.5 x 106 S m-1 |
Manganese Abundance & Isotopes
| Abundance earth's crust:0.1% by weight, 360 parts per million by moles | |
| Abundance solar system:10 parts per million by weight, 0.2 parts per million by moles | |
| Cost, pure:$6.5 100g | |
| Cost, bulk:$0.28 per 100g | |
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Source:
Manganese occurs mainly as the mineral pyrolusite (MnO2) and as rhodochrosite (MnCO3). Manganese can be found in manganese nodules on the ocean floor, but these are currently commercially unviable. Commercially, manganese is produced by reduction of its ores using aluminum. High purity manganese is made by electrolysis of manganese sulfate in solution. |
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Isotopes:
Manganese has 21 isotopes whose half-lives are known, with mass numbers 46 to 66. Of these, only one is stable, 55Mn. |
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Manganese Other
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Other:
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