Lithium hydroxide
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| Lithium hydroxide | |
|---|---|
| Image:Lithium hydroxide.jpg | |
| General | |
| Other names | Lithine |
| Molecular formula | LiOH |
| Molar mass | 23.95 g/mol |
| ppearance | white solid, hygroscopic |
| CAS number | [1310-65-2] |
| Properties | |
| Density and phase | 1.46 g/cm3, solid |
| Solubility in water | 12.8 g/100 ml (20 °C) |
| Melting point | 471 °C |
| Boiling point | 924 °C decomp. |
| Basicity (pKb) | ? |
| Structure | |
| Coordination geometry |
? |
| Crystal structure | Tetragonal |
| Thermodynamic data | |
| Standard enthalpy of formation ΔfH°solid |
-484.93 kJ/mol |
| Standard molar entropy S°solid |
42.81 J.K−1.mol−1 |
| Safety data | |
| EU classification | not listed |
| Flash point | non flammable |
| RTECS number | OJ6307070 |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Other anions | Lithium oxide |
| Other cations | Sodium hydroxide Potassium hydroxide |
| Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references |
|
Lithium hydroxide (LiOH) is a corrosive alkali. It is the product of mixing lithium and water. The reaction is as follows:
2Li + 2H2O → 2LiOH + H2
It is a very violent reaction, and so much heat is given off that the hydrogen produced burns with a bright purple flame. For this reason, lithium batteries must be kept away from water.
Lithium hydroxide is used in breathing gas purification systems for spacecraft (Lithium hydroxide canisters in the LEM 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 + 3H2O
Lithium Hydroxide (LiOH) is a white hygroscopic crystalline material. It is soluble in water, and slightly soluble in ethanol. There are commercial forms of the hydrated and anhydrous variations of lithium hydroxide. It is used for purification of gases and air (as a carbon dioxide absorbent), as a heat transfer medium, as a storage-battery electrolyte, and as a catalyst for polymerization. It is also used in ceramics, manufacturing other lithium compounds, and esterification specially for lithium stearate (which is used as a general purpose lubricating grease due to its high resistance to water and is useful at both high and low temperatures).
