Ruthenium
| General properties | |||||
|---|---|---|---|---|---|
| Name, symbol | Ruthenium, Ru | ||||
| Appearance | Silvery white metal | ||||
| Ruthenium in the periodic table | |||||
| |||||
| Atomic number | 44 | ||||
| Standard atomic weight (Ar) | 101.07(2) | ||||
| Group, block | VIII; d-block | ||||
| Period | period 5 | ||||
| Electron configuration | [Kr] 4d7 5s1 | ||||
per shell | 2, 8, 18, 15, 1 | ||||
| Physical properties | |||||
| Silvery white | |||||
| Phase | Solid | ||||
| Melting point | 2607 K (2334 °C, 4233 °F) | ||||
| Boiling point | 4423 K (4150 °C, 7502 °F) | ||||
| Density near r.t. | 12.45 g/cm3 | ||||
| when liquid, at | 10.65 g/cm3 | ||||
| Heat of fusion | 38.59 kJ/mol | ||||
| Heat of | 619 kJ/mol | ||||
| Molar heat capacity | 24.06 J/(mol·K) | ||||
| pressure | |||||
| Atomic properties | |||||
| Oxidation states | -4, -2, 1, 2, 3, 4, 5, 6, 7, 8 (a mildly acidic oxide) | ||||
| Electronegativity | Pauling scale: 2.2 | ||||
| energies |
1st: 710.2 kJ/mol 2nd: 1620 kJ/mol 3rd: 2747 kJ/mol | ||||
| Atomic radius | empirical: 134 pm | ||||
| Covalent radius | 146±7 pm | ||||
| Miscellanea | |||||
| Crystal structure | hexagonal close-packed (hcp) | ||||
| Speed of sound thin rod | 5970 m/s (at 20 °C) | ||||
| Thermal expansion | 6.4 µm/(m·K) (at 25 °C) | ||||
| Thermal conductivity | 117 W/(m·K) | ||||
| Electrical resistivity | 71 Ω·m (at 0 °C) | ||||
| Magnetic ordering | Paramagnetic | ||||
| Young's modulus | 447 GPa | ||||
| Shear modulus | 173 GPa | ||||
| Bulk modulus | 220 GPa | ||||
| Poisson ratio | 0.30 | ||||
| Mohs hardness | 6.5 | ||||
| Brinell hardness | 2160 MPa | ||||
| CAS Registry Number | 7440-18-8 | ||||
| History | |||||
| Naming | after Ruthenia (Latin for: medieval Kyivska Rus' region) | ||||
| Discovery and first isolation | Karl Ernst Claus (1844) | ||||
Ruthenium is a chemical element, a rare silvery-white transition metal, with the chemical symbol Ru and atomic number 44. It is a member of the so-called "platinum group metals".
Contents
Properties
Chemical
Ruthenium is highly resistant to corrosion. It is unaffected by mineral acids, even when hot. Aqua regia does not corrode ruthenium. However, as NurdRage noted in his ruthenium video, bleach (aka sodium hypochlorite solution) will slowly corrode it. Ruthenium is also attacked by fused alkali. Sodium peroxide also corrodes ruthenium, and this method is used in the extraction of the metal.
Physical
Ruthenium is a hard silvery-white platinum group metal. Ruthenium has a high melting point of 2334 °C and a boiling point of 4150 °C. It is quite dense, with a density at standard conditions of 12.45 g/cm3.
Availability
Ruthenium is sold by various chemical suppliers and metal companies. It can also be found on eBay.
Ruthenium can also be extracted from car catalytic converters.
Isolation
Ruthenium is best acquired as pure metal. It's not economical to extract the metal from its compounds or alloys.
Projects
- Make electrodes
- Catalysts
- Organoruthenium compounds
Handling
Safety
Ruthenium is non-toxic and does not cause any allergies on dermal contact. Ruthenium compounds, however, are quite toxic and should be handled with care.
Although this lies outside the scope of amateur chemistry, rings or other jewelry made of ruthenium should be removed before working with bleach due to the reactions mentioned above.
Storage
Ruthenium does not require special storage and can be stored in any container, bottle, etc.
Disposal
Due to ruthenium's rarity and the high price, it's best to recycle it, instead of throwing it away.
