Lithium hydroxide
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| Names | |
|---|---|
| IUPAC name
Lithium hydroxide | |
| Other names
Lithine | |
| Identifiers | |
1310-65-2  1310-66-3 (monohydrate)  | |
| 3D model (Jmol) | Interactive image |
| ChEBI | CHEBI:33979 |
| ChemSpider | 3802 |
| ECHA InfoCard | 100.013.804 |
| 68415 | |
| PubChem | 3939 |
| RTECS number | OJ6307070 |
| UNII | 903YL31JAS |
| UN number | 2680 |
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| Properties | |
| 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 (864 °F; 735 K) |
| Boiling point | 924 °C (1,695 °F; 1,197 K) decomposes |
| 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] | |
| Solubility in methanol | anhydrous: 9.76 g/100 g (20 °C, 48 hours mixing) monohydrate: 13.69 g/100 g (20 °C, 48 hours mixing)[2] |
| Solubility in ethanol | anhydrous: 2.36 g/100 g (20 °C, 48 hours mixing) monohydrate: 2.18 g/100 g (20 °C, 48 hours mixing)[2] |
| Solubility in isopropanol | anhydrous: 0 g/100 g (20 °C, 48 hours mixing) monohydrate: 0.11 g/100 g (20 °C, 48 hours mixing)[2] |
| Basicity (pKb) | -0.36[3] |
| Refractive index (nD) |
1.464 (anhydrous) 1.460 (monohydrate) |
| Thermochemistry | |
| 2.071 J/g K | |
| Std enthalpy of formation (ΔfH |
-20.36 kJ/g |
| Hazards | |
| Main hazards | Corrosive |
| Safety data sheet | ICSC 0913 ICSC 0914 (monohydrate) |
| NFPA 704 | |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
| LD50 (median dose) |
210 mg/kg (oral, rat)[4] |
| Related compounds | |
| Other anions |
Lithium amide |
| Other cations |
Sodium hydroxide Potassium hydroxide Rubidium hydroxide Caesium hydroxide |
| Related compounds |
Lithium oxide |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| verify (what is ?) | |
| 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, and is available commercially in anhydrous form and as the monohydrate (LiOH.H2O), both of which are strong bases. It is the weakest base among the alkali metal hydroxides.
Production and reactions
Lithium hydroxide is produced in a metathesis reaction between lithium carbonate and calcium hydroxide:[5]
- 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 usefulness at both high and low temperatures.
Carbon dioxide scrubbing
Lithium hydroxide is used in breathing gas purification systems for spacecraft, submarines, and rebreathers to remove carbon dioxide from exhaled gas by producing lithium carbonate and water:[6]
- 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
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.
Market
In 2012, the price of lithium hydroxide was about $5,000 to $6,000 per tonne.[7]
See also
References
- ↑ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3.
- 1 2 3 Khosravi, Javad (2007). "9: Results". PRODUCTION OF LITHIUM PEROXIDE AND LITHIUM OXIDE IN AN ALCOHOL MEDIUM. ISBN 978-0-494-38597-5.
- ↑ Lew. Kristi., Acids and Bases (Essential Chemistry). Infobase Publishing (2009). p43.
- ↑ http://chem.sis.nlm.nih.gov/chemidplus/rn/1310-65-2
- ↑ 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.
- ↑ http://investingnews.com/daily/resource-investing/energy-investing/lithium-investing/lithium-prices-2012/
External links
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Wikimedia Commons has media related to Lithium hydroxide. |
- International Chemical Safety Card 0913 (anhydrous)
- International Chemical Safety Card 0914 (monohydrate)