Caesium hydroxide is a strong base (pKa= 15.76), much like the other alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. In fact, caesium hydroxide is corrosive enough to dissolve through glass quickly.
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||149.912 g/mol|
|Appearance||Whitish-yellow deliquescent crystals|
|Melting point||272 °C (522 °F; 545 K)|
|300 g/100 mL at 30 °C|
|Solubility||Soluble in ethanol|
|Acidity (pKa)||15.76 |
Heat capacity (C)
Std enthalpy of
|H302, H314, H361, H373|
|P201, P202, P260, P264, P270, P280, P281, P301+P312, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P308+P313, P310, P314, P321, P330, P363, P405, P501|
|NFPA 704 (fire diamond)|
|Flash point||Not flammable|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|570 mg/kg (oral, rat)|
|NIOSH (US health exposure limits):|
|TWA 2 mg/m3|
IDLH (Immediate danger)
|Safety data sheet (SDS)||ICSC 1592|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
(what is ?)
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.
This compound is not commonly used in experiments due to the high extraction cost of caesium and its reactive behaviour. It acts in similar fashion to the compounds rubidium hydroxide and potassium hydroxide, although more reactive.