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Lithium chloride is a chemical compound with the formula LiCl. The salt is a typical ionic compound, although the small size of the Li+ ion gives rise to properties not seen for other alkali metal chlorides, such as extraordinary solubility in polar solvents (83g/100 mL of water at 20 °C) and its hygroscopic properties.
The salt forms crystalline hydrates
, unlike the other alkali metal chlorides. Mono-, tri-, and pentahydrates are known. It also absorbs up to four equivalents of ammonia
. As with any other ionic chlorides, solutions of lithium chloride can serve as a source of chloride
ion, e.g. forming a precipitate upon treatment with silver nitrate
- LiCl + AgNO3 → AgCl + LiNO3
Lithium chloride is produced by treatment of lithium carbonate
with hydrochloric acid
. It can in principle also be generated by the highly exothermic reaction
of lithium metal with either chlorine
or anhydrous hydrogen chloride
gas. To minimize hydrolysis
, anhydrous LiCl is prepared from the hydrate by heating with a stream of hydrogen chloride
Lithium chloride is mainly used for the production of lithium
metal by electrolysis
of a LiCl/KCl
melt at 600 °C
. LiCl is also used as a brazing flux
parts. It is used as a desiccant for drying air streams. In more specialized applications, lithium chloride finds some use in organic synthesis
, e.g. as an additive in the Stille reaction
. Also, in biochemical applications, it can be used to precipitate RNA
from cellular extracts.
Lithium chloride is also used as a flame colorant to produce dark red flames.
Lithium salts affect the central nervous system
; see lithium pharmacology
for more details. For a short time in the 1940s lithium chloride was manufactured as a substitute for salt, but this was prohibited after the toxic effects of the compound were recognized.
- Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.
- N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, 2nd ed., Butterworth-Heinemann, Oxford, UK, 1997.
- R. Vatassery, titration analysis of LiCl, sat'd in Ethanol by AgNO3 to precipitate AgCl(s). EP of this titration gives%Cl by mass.
- H. Nechamkin, The Chemistry of the Elements, McGraw-Hill, New York, 1968.