Ruthenium [Ru] 

CAS-ID: 7440-18-8

An: 44 N: 57

Am: 101.07 (2) g/mol

Group No: 8

Group Name: Precious metal or Platinum group metal

Block: d-block  Period: 5

State: solid

Colour: silvery white metallic Classification: Metallic

Boiling Point: 4423K (4150°C)

Melting Point: 2607K (2334°C)

Superconducting temperature: 0.49K (-272.66°C)

Density: 12.45g/cm3

Discovery Information

Who: Karl Klaus

When: 1844

Where: Russia

Name Origin

From Ruthenia, the Latin name of Russia.

 "Ruthenium" in different languages.

Sources

Found in the minerals pentlandite ((Fe,Ni)9S8) and pyroxinite. It is also possible to extract Ruthenium from spent nuclear fuel, which contains an average of 2 kg per metric ton.

Abundance

 Universe: 0.004 ppm (by weight)

 Sun: 0.005 ppm (by weight)

 Carbonaceous meteorite: 0.83 ppm

 Earth's Crust: 0.001 ppm

 Seawater: 7 x 10-7 ppm

Uses

Used to harden platinum and palladium. Also used in eye treatments, thickness meters for egg shells, fountain pen points, and electrical contacts. Aircraft magnetos use platinum alloy with 10% ruthenium.

The corrosion resistance of titanium is increased markedly by the addition of a small amount of ruthenium.

Recently, large metallo-organic complexes of ruthenium have been found to exhibit anti-tumor activity and the first of a new group of anti-cancer medicine are now in the stage of clinical trials.

History

Ruthenium was discovered and isolated by Russian scientist Karl Klaus in 1844. Klaus showed that ruthenium oxide contained a new metal and obtained 6 grams of ruthenium from the part of crude platinum that is insoluble in aqua regia.

Jöns Berzelius and Gottfried Osann nearly discovered ruthenium in 1827. The men examined residues that were left after dissolving crude platinum from the Ural Mountains in aqua regia. Berzelius did not find any unusual metals, but Osann thought he found three new metals and named one of them ruthenium.

The name derives from Ruthenia the Latin word for Rus', a historical area which includes present day Ukraine, Belarus, and parts of the Russia, Baltics, Slovakia and Poland. Karl Klaus called the element in honour of his birthland. He was born in Tartu, Estonia, then part of the Russian Empire.

It is also possible that Polish chemist Jedrzej Sniadecki isolated element 44 (which he called vestium) from platinum ores in 1807. However his work was never confirmed and he later withdrew his discovery claim.

Notes

It is not attacked by acids but is attacked by halogens at high temperatures. The corrosion resistance of titanium is increased markedly by the addition of a small amount of ruthenium.

Hazards

Ruthenium may be harmful if inhaled.

The compound ruthenium tetroxide, RuO4, similar to osmium tetroxide, is highly toxic and may explode. Ruthenium plays no biological role but does strongly stain human skin, may be carcinogenic and bio-accumulates in bone.