Lithium hydroxide
| Lithium hydroxide | |
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Lithium hydroxide |
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Other names
Lithine |
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| Identifiers | |
| CAS number | 1310-65-2  , 1310-66-3 (monohydrate) |
| PubChem | 3939 |
| ChemSpider | 3802 |
| UNII | 903YL31JAS |
| UN number | 2680 |
| ChEBI | CHEBI:33979 |
| RTECS number | OJ6307070 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | LiOH |
| Molar mass | 23.95 g/mol (anhydrous) 41.96 g/mol (monohydrate) |
| Appearance | hygroscopic white solid odorless |
| Density | 1.46 g/cm3 (anhydrous) 1.51 g/cm3 (monohydrate) |
| Melting point |
462 °C |
| Boiling point |
924 °C decomp. |
| Solubility in water | anhydrous:
12.7 g/100 mL (0 °C) 12.8 g/100 mL (20 °C) 17.5 g/100 mL (100 °C) monohydrate: 22.3 g/100 mL (10 °C) 26.8 g/100 mL (80 °C)[1] |
| Refractive index (nD) | 1.464 (anhydrous) 1.460 (monohydrate) |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
-20.36 kJ/g |
| Specific heat capacity, C | 2.071 J/g K |
| Hazards | |
| MSDS | ICSC 0913 ICSC 0914 (monohydrate) |
| EU Index | Not listed |
| Main hazards | Corrosive |
| NFPA 704 |
 0
3
0
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| Flash point | Non-flammable |
| Related compounds | |
| Other anions | Lithium amide |
| Other cations | Sodium hydroxide Potassium hydroxide Rubidium hydroxide Caesium hydroxide |
| Related compounds | Lithium oxide |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
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 (LiOH.H2O), both of which are strong bases.
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Production and reactions [edit]
Lithium hydroxide is produced in a metathesis reaction between lithium carbonate and calcium hydroxide:[2]
- 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 [edit]
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 usefulness at both high and low temperatures.
Carbon dioxide scrubbing [edit]
Lithium 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:[3]
- 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. One gram of anhydrous lithium hydroxide can remove 450 cm3 of carbon dioxide gas. The monohydrate loses its water at 100–110 °C.
Other uses [edit]
It is used as a heat transfer medium and 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 [edit]
References [edit]
- ^ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: 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 3-527-30673-0.
- ^ 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 [edit]
- International Chemical Safety Card 0913 (anhydrous)
- International Chemical Safety Card 0914 (monohydrate)
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