Page 92 - Encyclopedia of Chemical Compounds 3 Vols

F F
Al

F

OTHER NAMES:
Aluminum trifluoride

FORMULA:
AlF 3
ELEMENTS:
Aluminum Fluoride
Aluminum, fluorine
COMPOUND TYPE:
Inorganic salt
STATE:
Solid KE OVERVIEW
Aluminum fluoride (uh-LOO-min-um FLOR-ide) is a highly
83.98 g/mol stable compound that occurs as a white crystalline solid. It
MOLECULAR WEIGHT: Y
MELTING POINT: F resists the action of even strong solvents, such as hot con-

1291 C (2356 F; begins A centrated sulfuric acid. The compound often occurs as a
hydrate containing one or more molecules of water of hydra-

tion. The most common of these hydrates has the chemical
to sublime above C
formula AlF 3 3.5H 2 O, meaning that for every two molecules
1250 C [2280 F]) T
of aluminum fluoride in a crystal, there are seven molecules
Not applicable
BOILING POINT: S
of water. The major uses of aluminum fluoride are in a
SOLUBILITY:
variety of applications in the chemical industry.
Slightly soluble in
cold water, soluble in
hot water; insoluble HOW IT IS MADE
in alcohol, acetone,
Three methods are available for the preparation of alu-
and most organic
solvents minum fluoride commercially. In the first method, alumina
trihydrate (aluminum hydroxide; Al(OH) 3 ) is treated with
hydrofluoric acid (HF). A second method of preparation is
almost identical except that it takes place in the dry state
CHEMICAL COMPOUNDS 41