Caesium hydroxide

From WikiChem
Revision as of 09:26, 25 August 2009 by Physchim62 (talk | contribs) (Imported from http://en.wikipedia.org/w/index.php?title=Caesium_hydroxide&oldid=307094254)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search
Caesium hydroxide
Identifiers
CAS number [21351-79-12]
UN number 2682
RTECS FK9800000
Properties
Chemical formula CsOH
Molar mass 149.912 g/mol
Appearance whitish-yellow deliquescent crystals
Density 3.675 g/cm3, solid
Melting point

342.3°C

Solubility in water 300 g/100 ml at 30°C
Solubility soluble in ethanol[1]
Basicity (pKb) 1.76
Structure
Thermochemistry
Std enthalpy of formation ΔfHo298 −416.2 kJ·mol-1
Standard molar entropy So298 104.2 J·K−1·mol−1
Specific heat capacity C 69.9 J·mol-1·K-1[2]
Hazards
Material safety data sheet (MSDS) ICSC 1592
EU index number Not listed
Flash point Non flammable
Related compounds
Other anions Caesium oxide
Caesium fluoride
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.

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:

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

  1. Lide, David R. Handbook of Chemistry and Physics, 87 ed.; CRC Press: Boca Raton, FL, 1998; pp 4-51. ISBN 0849305942
  2. Lide, David R. Handbook of Chemistry and Physics, 87 ed.; CRC Press: Boca Raton, FL, 1998; pp 5-14. ISBN 0849305942

External links

Error creating thumbnail: Unable to save thumbnail to destination
Wikipedia-logo.png 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.