Barium tungstate is an
inorganic chemical compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemist ...
of
barium
Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element.
Th ...
and the
tungstate anion.
Synthesis and properties
Barium tungstate can be obtained from the
precipitation reaction
In an aqueous solution, precipitation is the process of transforming a dissolved substance into an insoluble solid from a super-saturated solution. The solid formed is called the precipitate. In case of an inorganic chemical reaction leading ...
between
barium nitrate and
ammonium paratungstate
Ammonium paratungstate (or APT) is a white crystalline salt with the chemical formula (NH4)10(H2W12O42)·4H2O. It is described as "the most important raw material for all
other tungsten products."
Production From tungsten ores
Tungsten ores, wh ...
or
sodium tungstate.
:Ba(NO
3)
2 + Na
2WO
4 → BaWO
4↓ + 2 NaNO
3
It is a white solid,
which at normal conditions forms tetragonal crystals similar to
scheelite, CaWO
4. Under pressures above 7 GPa, the compound undergoes transformation to a monoclinic structure similar to
fergusonite
Fergusonite is a mineral comprising a complex oxide of various rare-earth elements. The general chemical formula of fergusonite is (Y,REE)NbO4, where REE = rare-earth elements in solid solution with Y. Yttrium is usually dominant (the mineral in ...
, YNbO
4.
Uses
Barium tungstate can be used as a frequency shifter in
laser technology.
It has uses in X-ray photography and as a pigment.
References
{{Tungstates
Barium compounds
Tungstates