Difference between revisions of "Caesium hydroxide"
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| Name = Caesium hydroxide | | Name = Caesium hydroxide | ||
| Section1 = {{Chembox Identifiers | | Section1 = {{Chembox Identifiers | ||
| − | | CASNo = 21351-79- | + | | InChI = 1/Cs.H2O/h;1H2/q+1;/p-1 |
| + | | StdInChI = 1S/Cs.H2O/h;1H2/q+1;/p-1 | ||
| + | | CASNo = 21351-79-1 | ||
| CASNo_Ref = {{cascite}} | | CASNo_Ref = {{cascite}} | ||
| + | | EC-number = 244-344-1 | ||
| + | | ChemSpiderID = 56494 | ||
| RTECS = FK9800000 | | RTECS = FK9800000 | ||
| UNNumber = 2682 | | UNNumber = 2682 | ||
}} | }} | ||
| Section2 = {{Chembox Properties | | Section2 = {{Chembox Properties | ||
| + | | Reference = <ref>{{RubberBible62nd|page=B-92}}.</ref> | ||
| Formula = CsOH | | Formula = CsOH | ||
| − | | MolarMass = 149. | + | | MolarMass = 149.91 g/mol |
| − | | Appearance = whitish-yellow | + | | Appearance = whitish-yellow solid, deliquescent |
| Density = 3.675 g/cm<sup>3</sup>, solid | | Density = 3.675 g/cm<sup>3</sup>, solid | ||
| − | | MeltingPt = | + | | MeltingPt = 273.3 °C |
| − | | Solubility = | + | | Solubility = 395.5 g/100 ml at 15 °C |
| − | | | + | | Solubility1 = soluble |
| − | + | | Solvent1 = ethanol | |
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| Section4 = {{Chembox Thermochemistry | | Section4 = {{Chembox Thermochemistry | ||
| − | | DeltaHf = | + | | Reference = <ref>{{RubberBible87th|page=5-14}}.</ref> |
| − | | Entropy = 104.2 | + | | DeltaHf = −416.2 kJ/mol |
| − | | HeatCapacity = 69.9 | + | | Entropy = 104.2 J K<sup>−1</sup> mol<sup>−1</sup> |
| − | + | | HeatCapacity = 69.9 J K<sup>−1</sup> mol<sup>−1</sup> | |
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| Section7 = {{Chembox Hazards | | Section7 = {{Chembox Hazards | ||
| − | | ExternalMSDS = | + | | ExternalMSDS = {{ICSC-small|15|92}} |
| − | | EUIndex = | + | | EUIndex = not listed |
| − | | FlashPt = | + | | FlashPt = non-flammable |
}} | }} | ||
| Section8 = {{Chembox Related | | Section8 = {{Chembox Related | ||
| − | | OtherAnions = [[Caesium oxide | + | | OtherAnions = [[Caesium oxide]] |
| OtherCations = [[Lithium hydroxide]]<br/>[[Sodium hydroxide]]<br/>[[Potassium hydroxide]]<br/>[[Rubidium hydroxide]] | | OtherCations = [[Lithium hydroxide]]<br/>[[Sodium hydroxide]]<br/>[[Potassium hydroxide]]<br/>[[Rubidium hydroxide]] | ||
}} | }} | ||
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Due to its high reactivity, caesium hydroxide is extremely [[hygroscopic]]. Laboratory caesium hydoxide is typically a [[hydrate]]. | Due to its high reactivity, caesium hydroxide is extremely [[hygroscopic]]. Laboratory caesium hydoxide is typically a [[hydrate]]. | ||
| − | It is an anisotropic etchant of [[silicon]], exposing [[octahedron|octahedral]] planes. This technique can create pyramids and regularly-shaped etch pits for uses such as [[MEMS]]. It is known to have a higher selectivity to etch highly p-doped silicon than the more commonly used [[potassium hydroxide]]. | + | It is an anisotropic etchant of [[silicon]], exposing [[octahedron|octahedral]] planes. This technique can create pyramids and regularly-shaped etch pits for uses such as [[MEMS]]. It is known to have a higher selectivity to etch highly p-doped silicon than the more commonly used [[potassium hydroxide]].{{fact}} |
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]] but reacts chemically stronger than they do. | 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]] but reacts chemically stronger than they do. | ||
Caesium hydroxide can be obtained by the following chemical reaction: | Caesium hydroxide can be obtained by the following chemical reaction: | ||
| − | + | :2Cs + 2H<sub>2</sub>O → 2CsOH + H<sub>2</sub> | |
| − | : | + | The above reaction occurs explosively with enough force to shatter a [[Pyrex]] beaker. |
| − | |||
| − | The above reaction occurs explosively with enough force to shatter a [[Pyrex]] beaker | ||
==References== | ==References== | ||
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==External links== | ==External links== | ||
| − | * | + | *{{ICSC|15|92}} |
| − | * | + | *{{PGCH|0111}} |
[[Category:Caesium compounds]] | [[Category:Caesium compounds]] | ||
Revision as of 08:49, 25 August 2009
| Caesium hydroxide | |
|---|---|
| Identifiers | |
| InChI | InChI=1/Cs.H2O/h;1H2/q+1;/p-1 |
| Standard InChI | InChI=1S/Cs.H2O/h;1H2/q+1;/p-1 |
| CAS number | [] |
| EC number | |
| UN number | 2682 |
| RTECS | FK9800000 |
| ChemSpider | |
| Properties[1] | |
| Chemical formula | CsOH |
| Molar mass | 149.91 g/mol |
| Appearance | whitish-yellow solid, deliquescent |
| Density | 3.675 g/cm3, solid |
| Melting point |
273.3 °C |
| Solubility in water | 395.5 g/100 ml at 15 °C |
| Solubility in ethanol | soluble |
| Thermochemistry[2] | |
| Std enthalpy of formation ΔfH |
−416.2 kJ/mol |
| Standard molar entropy S |
104.2 J K−1 mol−1 |
| Specific heat capacity C | 69.9 J K−1 mol−1 |
| Hazards | |
| Material safety data sheet (MSDS) | ICSC |
| EU index number | not listed |
| Flash point | non-flammable |
| Related compounds | |
| Other anions | Caesium oxide |
| Other cations | Lithium hydroxide Sodium hydroxide Potassium hydroxide Rubidium hydroxide |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
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 hydoxide is typically a hydrate.
It is an anisotropic etchant of silicon, exposing octahedral planes. This technique can create pyramids and regularly-shaped etch pits for uses such as MEMS. It is known to have a higher selectivity to etch highly p-doped silicon than the more commonly used potassium hydroxide.[ref. needed]
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 but reacts chemically stronger than they do.
Caesium hydroxide can be obtained by the following chemical reaction:
- 2Cs + 2H2O → 2CsOH + H2
The above reaction occurs explosively with enough force to shatter a Pyrex beaker.
References
External links
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This page was originally imported from Wikipedia, specifically this version of the article "Caesium hydroxide". Please see the history page on Wikipedia for the original authors. This WikiChem article may have been modified since it was imported. It is licensed under the Creative Commons Attribution–Share Alike 3.0 Unported license. |
