Lithium chloride is a

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

Li Cl. The

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

is a typical

ionic compound In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions (Cation, cations) and negatively charged ions (Anion, anions), which results in a compound with no net electric charge (electrica ...

(with certain covalent characteristics), 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

solvent A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas ...

s (83.05 g/100 mL of water at 20 °C) and its

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption (chemistry), absorption or adsorption from the surrounding Natural environment, environment, which is usually at normal or room temperature. If water mol ...

properties.

Chemical properties

The salt forms crystalline hydrates, unlike the other alkali metal chlorides. Mono-, tri-, and pentahydrates are known. The anhydrous salt can be regenerated by heating the hydrates. LiCl also absorbs up to four equivalents of

ammonia Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...

/mol. As with any other ionic chloride, solutions of lithium chloride can serve as a source of

chloride The term chloride refers to a compound or molecule that contains either a chlorine anion (), which is a negatively charged chlorine atom, or a non-charged chlorine atom covalently bonded to the rest of the molecule by a single bond (). The pr ...

ion, e.g., forming a precipitate upon treatment with silver nitrate: : LiCl + AgNO₃ → AgCl + LiNO₃

Preparation

Lithium chloride is produced by treatment of lithium carbonate with

hydrochloric acid Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

. Anhydrous LiCl is prepared from the hydrate by heating in a stream of

hydrogen chloride The Chemical compound, compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hyd ...

Uses

Commercial applications

Lithium chloride is mainly used for the production of

lithium Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...

metal by

electrolysis In chemistry and manufacturing, electrolysis is a technique that uses Direct current, direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of c ...

of a LiCl/ KCl melt at . LiCl is also used as a brazing flux for

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

automobile A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, peopl ...

parts. It is used as a desiccant for drying air streams. In more specialized applications, lithium chloride finds some use in

organic synthesis Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...

, e.g., as an additive in the Stille reaction. Also, in biochemical applications, it can be used to precipitate

RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...

from cellular extracts. Lithium chloride is also used as a flame colorant to produce dark red flames.

Niche uses

Lithium chloride is used as a relative humidity standard in the calibration of

hygrometer A hair tension dial hygrometer with a nonlinear scale. A hygrometer is an instrument that measures humidity: that is, how much water vapor is present. Humidity measurement instruments usually rely on measurements of some other quantities, such a ...

s. At a saturated solution (45.8%) of the salt will yield an equilibrium relative humidity of 11.30%. Additionally, lithium chloride can be used as a hygrometer. This deliquescent salt forms a self-solution when exposed to air. The equilibrium LiCl concentration in the resulting solution is directly related to the relative humidity of the air. The percent relative humidity at can be estimated, with minimal error in the range , from the following first-order equation: RH=107.93-2.11C, where C is solution LiCl concentration, percent by mass. Molten LiCl is used for the preparation of

carbon nanotube A carbon nanotube (CNT) is a tube made of carbon with a diameter in the nanometre range ( nanoscale). They are one of the allotropes of carbon. Two broad classes of carbon nanotubes are recognized: * ''Single-walled carbon nanotubes'' (''S ...

graphene Graphene () is a carbon allotrope consisting of a Single-layer materials, single layer of atoms arranged in a hexagonal lattice, honeycomb planar nanostructure. The name "graphene" is derived from "graphite" and the suffix -ene, indicating ...

and lithium niobate. Lithium chloride has been shown to have strong acaricidal properties, being effective against ''

Varroa destructor ''Varroa destructor'', the Varroa mite, is an ectoparasite, external parasitic mite that attacks and feeds on honey bees and is one of the most damaging honey bee pests in the world. A significant mite infestation leads to the death of a honey b ...

'' in populations of

honey bee A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to mainland Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the ...

s. Lithium chloride is used as an aversive agent in lab animals to study conditioned place preference and aversion.

Precautions

Lithium salts affect the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

in a variety of ways. While the citrate,

carbonate A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...

, and orotate salts are currently used to treat

bipolar disorder Bipolar disorder (BD), previously known as manic depression, is a mental disorder characterized by periods of Depression (mood), depression and periods of abnormally elevated Mood (psychology), mood that each last from days to weeks, and in ...

, other lithium salts including the chloride were used in the past. For a short time in the 1940s lithium chloride was manufactured as a salt substitute for people with hypertension, but this was prohibited after the toxic effects of the compound ( tremors,

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

) were recognized. It was, however, noted by J. H. Talbott that many symptoms attributed to lithium chloride toxicity may have also been attributable to sodium chloride deficiency, to the diuretics often administered to patients who were given lithium chloride, or to the patients' underlying conditions.

References

* ''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.

External links

Radiochemical measurements of activity coefficients, from Betts & MacKenzie, Can. J. Chem.
{{Authority control Chlorides Alkali metal chlorides Lithium salts Metal halides Mood stabilizers Desiccants Rock salt crystal structure