Molybdenum
Molybdenum General
Name:Molybdenum | Symbol:Mo |
Type:Transition Metal | Atomic weight:95.94 |
Density @ 293 K: 10.2 g/cm3 | Atomic volume:9.4 cm3/mol |
Discovered:
Carl W. Scheele extracted molybdenum oxide from the mineral molybdenite (molybdena) in 1778. He concluded that the mineral contained a new element but did not isolate it. In 1781, Peter J. Hjelm isolated the metal by reducing the oxide with carbon. The element name comes from the Greek word 'molybdos', meaning lead. |
Molybdenum States
State (s, l, g):solid | |
Melting point:2896 K (2623 °C) | Boiling point:4913 K (4640 °C) |
Molybdenum Energies
Specific heat capacity: 0.25 J g-1 K-1 | Heat of atomization:659 kJ mol-1 |
Heat of fusion:32.0 kJ mol-1 | Heat of vaporization :598 kJ mol-1 |
1st ionization energy:684.9 kJ mol-1 | 2nd ionization energy:1588.2 kJ mol-1 |
3rd ionization energy:2620.5 kJ mol-1 | Electron affinity:72 kJ mol-1 |
Molybdenum Oxidation & Electrons
Shells:2,8,18,13,1 | Electron configuration:[Kr] 4d5 5s1 |
Minimum oxidation number:-2 | Maximum oxidation number:6 |
Min. common oxidation no.:0 | Max. common oxidation no.:6 |
Electronegativity (Pauling Scale):2.16 | Polarizability volume:12.8 Å3 |
Molybdenum Appearance & Characteristics
Structure:bcc: body-centered cubic | Color:silvery-white |
Hardness: 5.5 mohs | |
Harmful effects:
Molybdenum is toxic in all but small quantaties. |
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Characteristics:
Molybdenum is a silvery-white, high-melting metal. Molybdenum is one of the five major refractory metals (metals with very high resistance to heat and wear). The other refactory metals are tungsten, tantalum, rhenium and niobium. Uses: Molybdenum's strength and resistance to expanding or softening at high temperatures is particularly sought after in critical areas where high temperatures are common, such as in nuclear power plants and aircraft engines. |
Molybdenum Reactions
Reaction with air:w/ht, ⇒ MoO3 | Reaction with 6 M HCl:none |
Reaction with 15 M HNO3:none | Reaction with 6 M NaOH: |
Molybdenum Compounds
Oxide(s):MoO2, MoO3 | Chloride(s):MoCl2, MoCl3 , MoCl4, MoCl5, MoCl6 |
Hydride(s): |
Molybdenum Radius
Atomic radius:139 pm | Ionic radius (1+ ion):pm |
Ionic radius (2+ ion):pm | Ionic radius (3+ ion):83 pm |
Ionic radius (2- ion):pm | Ionic radius (1- ion):pm |
Molybdenum Conductivity
Thermal conductivity:138 W m-1 K-1 | Electrical conductivity:17.3 x 106 S m-1 |
Molybdenum Abundance & Isotopes
Abundance earth's crust:1.2 parts per million by weight, 0.2 parts per million by moles | |
Abundance solar system:9 parts per billion by weight, 0.1 part per billion by moles | |
Cost, pure: $44 per 100g | |
Cost, bulk:$ per 100g | |
Source:
Molybdenum is not found free in nature. The main ore of molybdenum is molybdenite, (molybdenum disulfide, MoS2). It also occurs in wulfenite (lead molybdate) and powellite (calcium molybdate). Comercially, the metal is obtained by mining molybdenite directly and it is also recovered as a by-product of copper mining. |
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Isotopes:
Molybdenum has 24 isotopes whose half-lives are known with mass numbers from 86 to 110. Of these, six are stable: 92Mo, 94Mo, 95Mo, 96Mo, 97Mo and 98Mo. The most naturally abundant is 98Mo at 24.1%. |
Molybdenum Other
Other:
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