Ru
RUTHENIUM
( L. Ruthenia, Russia)
Ru at. wt. 101.07
at. no. 44
m.p. 2310°C
b.p. 3900°C
sp. gr. 12.41 (20°C)
valence 0, 1, 2, 3, 4, 5, 6, 7, 8.
Electronic configuration
| SHELL |
K |
L |
M |
N |
O |
P |
Q |
| SUB SHELL |
He |
Neon |
Argon |
Krypton |
Xenon |
Radon |
Eka-radon |
| 1s |
2s 2p |
3s 3p |
3d 4s 4p |
4d 5s 5p |
4f 5d 6s 6p |
5f 6d 7s 7p |
| Ruthenium
|
1s22s22p63s23p63d104s24p64d75s1 |
|
|
| Symbol
|
5F5 |
Ruthenium was found by Berzelius and Osann in 1827
while examined the residues left afler dissolving crude platinum
from the Ural Mts. in aqua regia. While Berzelius found no
unusual metals. Osann thought he found three new metals,
one of which he named ruthenium. In 1844 Klaus, generally
recognized as the discoverer, showed that Osann's ruthenium
oxide was very impure and that it contained a new metal.
Klaus obtained 6 gm. of ruthenium from the portion of
crude platinum that is insoluble in aqua regia. A member
of the platinum group, ruthenium occurs native with other
members of the group in ores found in the Ural Mts. and
in North and South America. It is also found along with
other platinum metals in small but commercial quantifies
in pentlandite of the Sudbury, Ontario, nickel-mining
region, and in pyroxinite deposits of South Africa. The
metal is isolated commercially by a complex chemical
process, the final stage of which is the hydrogen reduction
of ammonium ruthenium chloride, which yields a powder.
The powder is consolidated by powder metallurgy techniques or by argon-arc welding. Ruthenium is a hard, white
metal and has four crystal modifications. It does not tarnish
at room temperatures, but oxidizes in air at about 800°C.
The metal is not attacked by hot or cold acids or aqua
regia, but when potassium chlorate is added to the solution,
it oxidizes explosively. Itis attacked by halogens, hydroxides,
etc. Ruthenium can be plated by electrodeposition or by
thermal decomposition methods. The metal is one of the
most effective hardeners for platinum and palladium, and
is alloyed with these metals to make electrical contacts for
severe wear resistance. A ruthenium-molybdenum alloy is
said to be superconductive at 10.60K. The corrosion resistance of titanium is improved a hundredfold by addition
of 0.1 % ruthenium. It is a versatile catalyst. Compounds in
at least eight oxidation states have been found, but of these,
the + 2, +3, and + 4 states are the most common. Ruthen-
ium tetraoxide, like osmium tetraoxide, is highly toxic.
Ruthenium compounds show a marked resemblance to
those of osmium. The metal is priced at about $4/gm. or
$60/troy ounce.
© 1999 F. Davies
Delphi O.E.M. Co.
All rights reserved
