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| Names | |
|---|---|
| IUPAC name Lithium bromide | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider |
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| ECHA InfoCard | 100.028.582 |
| EC Number |
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| RTECS number |
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| UNII | |
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| Properties | |
| LiBr | |
| Molar mass | 86.845 g/mol[1] |
| Appearance | Whitehygroscopic solid[1] |
| Density | 3.464 g/cm3[1] |
| Melting point | 550 °C (1,022 °F; 823 K)[1] |
| Boiling point | 1,300 °C (2,370 °F; 1,570 K)[1] |
| 143 g/100 mL (0 °C) 166.7 g/100 mL (20 °C) 266 g/100 mL (100 °C)[2] | |
| Solubility | soluble inmethanol,ethanol,[1]ether,[1]acetone slightly soluble inpyridine |
| −34.3·10−6 cm3/mol[3] | |
Refractive index (nD) | 1.7843 (589 nm)[4] |
| Structure[5] | |
| Cubic,Pearson symbol cF8, No. 225 | |
| Fm3m | |
a = 0.5496 nm | |
| Thermochemistry[6] | |
Std molar entropy(S⦵298) | 74.3 J/mol K |
Std enthalpy of formation(ΔfH⦵298) | −351.2 kJ/mol |
Gibbs free energy(ΔfG⦵) | −342.0 kJ/mol |
| Hazards | |
| GHS labelling: | |
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| Warning | |
| H315,H317,H319[7] | |
| NFPA 704 (fire diamond) | |
| Flash point | Not-flammable |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 1800 mg/kg (oral, rat)[8] |
| Related compounds | |
Otheranions | Lithium fluoride Lithium chloride Lithium iodide |
Othercations | Sodium bromide Potassium bromide Rubidium bromide Caesium bromide |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Lithium bromide (LiBr) is achemical compound oflithium andbromine. Its extremehygroscopic character makes LiBr useful as adesiccant in certainair conditioning systems.[9]
LiBr is prepared by treating an aqueous suspension of lithium carbonate withhydrobromic acid or by reactinglithium hydroxide with bromine.[9] It forms several crystallinehydrates, unlike the other alkali metal bromides.[10]
Lithium hydroxide and hydrobromic acid (aqueous solution of hydrogen bromide) will precipitate lithium bromide in the presence of water.
A 50–60% aqueous solution of lithium bromide is used in air-conditioning systems asdesiccant. It is also used in absorption chilling along with water (seeabsorption refrigerator). Solid LiBr is a useful reagent inorganic synthesis. It is included into oxidation andhydroformylation catalysts; it is also used for deprotonation and dehydration of organic compounds containing acidic protons, and for the purification ofsteroids andprostaglandins.[9]
Lithium bromide was used as asedative beginning in the early 1900s, but it fell into disfavor in the 1940s as newer sedatives became available and when some heart patients died after using the salt substitute lithium chloride.[11] Likelithium carbonate andlithium chloride, it was used as treatment forbipolar disorder.
Lithium salts arepsychoactive and somewhat corrosive. Heat is quickly generated when lithium bromide is dissolved into water because it has a negativeenthalpy of solution.
