Caesium hydroxide
| Caesium hydroxide | |
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| Identifiers | |
| CAS number | 21351-79-1  |
| ChemSpider | 56494 |
| EC-number | 244-344-1 |
| UN number | 2682 |
| ChEBI | CHEBI:33988 |
| RTECS number | FK9800000 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | CsOH |
| Molar mass | 149.912 g/mol |
| Appearance | Whitish-yellow deliquescent crystals |
| Density | 3.675 g/cm3 |
| Melting point |
342.3 °C |
| Solubility in water | 300 g/100 mL at 30 °C |
| Solubility | Soluble in ethanol[1] |
| Basicity (pKb) | 1.76 |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
−416.2 kJ·mol-1 |
| Standard molar entropy S |
104.2 J·K−1·mol−1 |
| Specific heat capacity, C | 69.9 J·mol-1·K-1[2] |
| Hazards | |
| MSDS | ICSC 1592 |
| EU Index | Not listed |
| Flash point | Non flammable |
| Related compounds | |
| Other anions | Caesium oxide Caesium fluoride |
| Other cations | Lithium hydroxide Sodium hydroxide Potassium hydroxide Rubidium hydroxide |
 (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 | |
Caesium hydroxide (CsOH) is a chemical compound consisting of an atom of caesium and a hydroxide group (also known as hydroxyl). It is a powerful base, much like 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.
[edit] References
- ^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 4–51, ISBN 0-8493-0594-2
- ^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 5–14, ISBN 0-8493-0594-2
[edit] External links
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