Caesium hydroxide
| Names | |
|---|---|
| Other names
Cesium hydrate
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| Identifiers | |
21351-79-1  |
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| ChEBI | CHEBI:33988 |
| ChemSpider | 56494 |
| EC Number | 244-344-1 |
| Jmol 3D model | Interactive image |
| RTECS number | FK9800000 |
| UN number | 2682 |
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| Properties | |
| CsOH | |
| Molar mass | 149.912 g/mol |
| Appearance | Whitish-yellow deliquescent crystals |
| Density | 3.675 g/cm3 |
| Melting point | 272 °C (522 °F; 545 K)[3] |
| 300 g/100 mL at 30 °C | |
| Solubility | Soluble in ethanol[1] |
| Basicity (pKb) | -1.76[2] |
| Thermochemistry | |
| 69.9 J·mol−1·K−1[4] | |
|
Std molar
entropy (S |
104.2 J·K−1·mol−1 |
|
Std enthalpy of
formation (ΔfH |
−416.2 kJ·mol−1 |
| Vapor pressure | {{{value}}} |
| Related compounds | |
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Other anions
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Caesium oxide Caesium fluoride |
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Other cations
|
Lithium hydroxide Sodium hydroxide Potassium hydroxide Rubidium hydroxide |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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| Infobox references | |
Caesium hydroxide (CsOH) is a chemical compound consisting of an ion of caesium and a hydroxide ion. It is a strong base (pKb=-1.76), much like the other alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. In fact, caesium hydroxide is powerful enough to quickly corrode through glass.
Due to its high reactivity, caesium hydroxide is extremely hygroscopic. Laboratory caesium hydroxide is typically a hydrate.
It is an anisotropic etchant of silicon, exposing octahedral planes. This technique can form pyramids and regularly shaped etch pits for uses such as Microelectromechanical systems. It is known to have a higher selectivity to etch highly p-doped silicon than the more commonly used potassium hydroxide.
However, this compound is not usually used in experiments as the extraction of caesium is very expensive and the fact that it behaves very much like rubidium hydroxide and potassium hydroxide although it is more reactive than they are.
Caesium hydroxide can be obtained by the following chemical reaction:
- 2 Cs + 2 H2O → 2 CsOH + H2
The above reaction occurs explosively with enough force to shatter a Pyrex beaker. Caesium metal will react with ice above −116 °C.
References
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ http://www.periodensystem-online.de/index.php?show=list&id=acid&prop=pKb-Werte&sel=oz&el=92
- ↑ http://www.inchem.org/documents/icsc/icsc/eics1592.htm
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
