Historical
Facts and Elements Uses:
In the mid 18th century analysis of Siberian "red lead" (PbCrO4, crocoite)
from Siberia showed that it contained
quite a lot of lead, but also a further material. This was eventually identified
as chromium oxide. Chromium oxide was
discovered in 1797 by Louis-Nicholas Vauquelin, who prepared the metal
himself in the following year. Starting from
crocoite the procedure was to powder the mineral and to precipitate the
lead out through its reaction with hydrochloric
acid (HCl in water). The residue was chromium oxide, CrO3. Heating this
oxide in an oven in the presence of charcoal as a reducing agent gave the
metal itself. Vauquelin also analyzed an emerald from Peru and discovered
that its green color is because of the presence of the new element, chromium.
In fact, the name chromium is from the Greek word "chroma" meaning
"color", so named because of the many different colored compounds displayed
by chromium.
Chromium is a silver white with a blushing tinge. Chromium is
not affected by oxygen at ordinary temperatures. Electron plated
Chromium is used in car bumpers, door handles, table ware, and ornaments,
it is used in all of this because it miantains its bright surface. The
oxides are also used for paints.
Chromium is found in Zimbabwe, Russia, Transvaal, Turkey, Iran, Albania,
Finland, Madagascar, and the Phillippines. |
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