Ruthenium

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Ruthenium,  44Ru
General properties
Name, symbol Ruthenium, Ru
Appearance Silvery white metal
Ruthenium in the periodic table
Fe

Ru

Os
TechnetiumRutheniumRhodium
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)
· references

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".

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.

References

Relevant Sciencemadness threads