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| Names | |
|---|---|
| IUPAC name Lithium hydroxide | |
| Other names Lithine | |
| Identifiers | |
| CAS Number | |
| 3D model (JSmol) | |
| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.013.804 
|
| PubChem CID | |
| RTECS number |
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| UNII | |
| UN number | 2680 |
| CompTox Dashboard (EPA) | |
InChI
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SMILES
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| Properties | |
| Chemical formula | LiOH |
| Molar mass | 23.95 g/mol |
| Appearance | hygroscopic white solid odorless |
| Density | 1.46 g/cm (anhydrous) 1.51 g/cm (monohydrate) |
| Melting point | 462 °C |
| Boiling point | 924 °C decomp. |
| Solubility in water | anhydrous: 12.8 g/100 mL (20 °C) 12.5 g/100 mL (25 °C) 17.5 g/100 mL (100 °C) monohydrate: 22.3 g/100 mL (10 °C) 26.8 g/100 mL (100 °C) |
| Refractive index (nD) | 1.464 (anhydrous) 1.460 (monohydrate) |
| Thermochemistry | |
| Heat capacity (C) | 2.071 J/g K |
| Std enthalpy of formation (ΔfH298) |
-20.36 kJ/g |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
| Main hazards | Corrosive |
| NFPA 704 (fire diamond) |
 |
| Flash point | Non-flammable |
| Related compounds | |
| Other anions | Lithium amide |
| Other cations | Sodium hydroxide Potassium hydroxide Rubidium hydroxide Caesium hydroxide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa).
 Y verify (what is ?)
Infobox references
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Lithium hydroxide is an inorganic compound with the formula LiOH. It is a white hygroscopic crystalline material. It is soluble in water, and slightly soluble in ethanol. It is available commercially in anhydrous form and as the monohydrate (LiOHH2O), both of which are strong bases.
Production and reactions
Lithium hydroxide is produced in a metathesis reaction between lithium carbonate and calcium hydroxide:
- Li2CO3 + Ca(OH)2 → 2 LiOH + CaCO3
The initially produced hydrate is dehydrated by heating under vacuum up to 180 °C.
In the laboratory, lithium hydroxide arises by the action of water on lithium or lithium oxide. The equations for these processes follow:
- 2 Li + 2 H2O → 2 LiOH + H2
- Li2O + H2O → 2 LiOH
Typically, these reactions are avoided.
Although lithium carbonate is more widely used, the hydroxide is an effective precursor to lithium salts, e.g.
- LiOH + HF → LiF + H2O.
Applications
Lithium hydroxide is mainly consumed for the production of lithium greases. A popular lithium grease is lithium stearate, which is a general purpose lubricating grease due to its high resistance to water and being useful at both high and low temperatures.
Carbon dioxide scrubbing
Further information: carbon dioxide scrubberLithium hydroxide is used in breathing gas purification systems for spacecraft (Lithium hydroxide canisters in the Lunar Module and Command/Service Module (after modification) were lifelines for the Apollo 13 astronauts), submarines, and rebreathers to remove carbon dioxide from exhaled gas by producing lithium carbonate and water:
- 2 LiOH·H2O + CO2 → Li2CO3 + 3 H2O
Or,
- 2LiOH + CO2 → Li2CO3 + H2O
The latter, anhydrous hydroxide is preferred for its lower mass and lesser water production for respirator systems in spacecraft. 1 gram of anhydrous lithium hydroxide can remove 450 cm of carbon dioxide gas. The monohydrate loses its water at 100-110 °C.
Other uses
It is used as a heat transfer medium, as a storage-battery electrolyte. It is also used in ceramics and some Portland cement formulations. Lithium hydroxide (isotopically enriched in lithium-7) is used to alkalize the reactor coolant in pressurized water reactors for corrosion control.
See also
References
- Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, Florida: CRC Press. ISBN 0-8493-0487-3.
- Wietelmann, U; Bauer, RJ (2000). "Lithium and Lithium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a15_393. ISBN 3527306730.
- Jaunsen, JR (1989). "The Behavior and Capabilities of Lithium Hydroxide Carbon Dioxide Scrubbers in a Deep Sea Environment". US Naval Academy Technical Report. USNA-TSPR-157. Retrieved 2008-06-17.
External links
- International Chemical Safety Card 0913 (anhydrous)
- International Chemical Safety Card 0914 (monohydrate)