Rhenium
Rhenium General
| Name:Rhenium | Symbol:Re |
| Type:Transition Metal | Atomic weight:186.207 |
| Density @ 293 K:21.0 g/cm3 | Atomic volume:8.85 cm3/mol |
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Discovered:
Before rhenium was discovered, it was accurately predicted by Henry Moseley in 1914, based on his examination of the periodic table. Walter Noddack, Ida Tacke, and Otto Berg first detected the element in platinum ores and columbite in 1925. In 1928 they isolated one gram of the metal from 660 kilograms molybdenite. Rhenium was the last naturally stable element to be discovered. The element name comes from Latin word 'Rhenus', meaning Rhine. |
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Rhenium States
| State (s, l, g): solid | |
| Melting point:3459 K (3186 °C) | Boiling point:5869 K (5596 °C) |
Rhenium Energies
| Specific heat capacity:0.13 J g-1 K-1 | Heat of atomization: 776 kJ mol-1 |
| Heat of fusion:33.20 kJ mol-1 | Heat of vaporization : 715.0 kJ mol-1 |
| 1st ionization energy:760 kJ mol-1 | 2nd ionization energy: 1260 kJ mol-1 |
| 3rd ionization energy:2510 kJ mol-1 | Electron affinity:14 kJ mol-1 |
Rhenium Oxidation & Electrons
| Shells:2,8,18,32,13,2 | Electron configuration:[Xe] 4f14 5d5 6s2 |
| Minimum oxidation number: -3 | Maximum oxidation number:7 |
| Min. common oxidation no.:0 | Max. common oxidation no.:4 |
| Electronegativity (Pauling Scale):1.9 | Polarizability volume:9.7 Å3 |
Rhenium Appearance & Characteristics
| Structure:hcp: hexagonal close pkd | Color:silvery-white |
| Hardness:7.0 mohs | |
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Harmful effects:
Rhenium and its compounds are used in such small quantities that their toxicity is yet to be established. |
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Characteristics:
Rhenium is a rare, silvery-white, lustrous, dense metal. It resists corrosion and oxidation but slowly tarnishes in moist air. Of the elements, only carbon and tungsten have higher melting points and only iridium, osmium, and platinum are more dense. Rhenium is one of the five major refractory metals (metals with very high resistance to heat and wear). The other refactory metals are tungsten, molybdenum, tantalum and niobium. Rhenium compounds include oxides, halides and sulfides. Uses: Rhenium is used with platinum as catalysts in the production of lead-free, high-octane gasoline. The metal is used in alloys for jet engines and in tungsten and molybdenum based alloys. It is widely used as filaments for mass spectrographs. Rhenium is also used as an electrical contact material. Rhenium catalysts are exceptionally resistant to poisoning from nitrogen, sulfur and phosphorous and are useful in the hydrogenation of fine chemicals. |
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Rhenium Reactions
| Reaction with air:mild, w/ht ⇒ Re2O7 (rhenium heptoxide) | Reaction with 6 M HCl:none |
| Reaction with 15 M HNO3:mild, ⇒ HReO4 (perrhenic acid) | Reaction with 6 M NaOH:none |
Rhenium Compounds
| Oxide(s):ReO2, ReO3, Re2O3, Re2O5, Re2 | Chloride(s):Re3Cl9, ReCl4, ReCl5, ReCl6 |
| Hydride(s):none |
Rhenium Radius
| Atomic radius:137 pm | Ionic radius (1+ ion): pm |
| Ionic radius (2+ ion): pm | Ionic radius (3+ ion): pm |
| Ionic radius (2- ion): pm | Ionic radius (1- ion): pm |
Rhenium Conductivity
| Thermal conductivity:48.0 W m-1 K-1 | Electrical conductivity:5.8 x 106 S m-1 |
Rhenium Abundance & Isotopes
| Abundance earth's crust: 7 parts per billion by weight, 0.8 parts per billion by moles | |
| Abundance solar system:100 parts per trillion by weight, 0.5 parts per trillion by moles | |
| Cost, pure:$1600 per 100g | |
| Cost, bulk:$ per 100g | |
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Source:
Rhenium is not found free in nature but is found in small quantities in platinum and molybdenum ores and many minerals. Commercially, rhenium is recovered as a by-product of copper refining. |
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Isotopes:
Rhenium has 33 isotopes whose half-lives are known, with mass numbers from 160 to 192. Of these, one is stable: 185Re. Naturally the most common isotope is 187Re, with an abundance of 62.6% and a very long half-life of 4.35 x1010 years. |
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Rhenium Other
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Other:
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