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Rubidium hydroxide

Rubidium hydroxide
Systematic name Rubidium hydroxide
Synonym Rubidium(I) hydroxide
Empirical formula RbOH
Ionic formula Rb+(OH)-
Molar mass 102.48 g/mol
Appearance white solid, hygroscopic
CAS number [1310-82-3]
Density and phase 3.203 g/cm3, solid
Solubility in water 180 g/100 ml (15 °C)
Melting point 301 °C
Boiling point  ? °C (? K)
pKb -1.99
Thermodynamic data
Standard enthalpy
of formation
−413.8 kJ/mol
Standard molar entropy
 ? J.K−1.mol−1
Hazard symbol C: corrosive
Risk description R22, R34
Safety description S26, S27, S37, S39, S45
Related compounds
Other anions Rubidium fluoride
Rubidium chloride
Rubidium bromide
Rubidium iodide
Rubidium hydride
Rubidium hydroxide
Rubidium oxide
Rubidium sulfide
Rubidium selenide
Rubidium telluride
Other cations Lithium hydroxide
Sodium hydroxide
Potassium hydroxide
Caesium hydroxide
and all other hydroxides
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Infobox disclaimer and references

Rubidium Hydroxide (RbOH) is a strong basic chemical and alkali that is formed by one rubidium ion and one hydroxide ion.

Rubidium hydroxide does not appear in nature. However it can be obtained by synthesis from rubidium oxide. In addition, rubidium hydroxide is commercially available in form of an aqueous solution from a few suppliers.

Rubidium hydroxide is highly corrosive, therefore suitable protective clothing, gloves and eye-face protection are required when handling this material.



Rubidium hydroxide can be synthesized from rubidium oxide by dissolving the oxide into water:

Rb2O (s) + H2O (l) → 2RbOH (aq)

Rubidium hydroxide is also commercially available from a certain number of chemical suppliers in form of 50% or 99% aqueous solution at multiples of 5g.


Rubidium hydroxide is rarely used in industrial processes because potassium hydroxide and sodium hydroxide can perform nearly all the industrial functions of rubidium hydroxide in a less violent and hence safer way.

Rubidium hydroxide is used in scientific research. It is often used sparingly to prevent waste of the expensive element rubidium.

Despite the fact that rubidium hydroxide is rarely used in normal industrial processes, it is notable that the synthesis of nearly all rubidium compounds involves rubidium hydroxide as an intermediate. Natural rubidium oxide is added to water, and the resulting reaction forms soluble rubidium hydroxide as a product.

Hazard prevention

Rubidium hydroxide is a corrosive compound that causes immediate burns to the skin on contact. Ultimate care must be carried out when handling this chemical.

In the laboratory, protective clothing, gloves, and eye-face protection made from alkali-resistant materials are to be worn to prevent injury caused by accidental leakage of rubidium hydroxide onto human skin.

Dilution of this strong alkali must be done by adding the hydroxide slowly into the beaker of water.

In addition, chemical experiments on this compound must be performed with caution to prevent the great amount of heat released in an exothermic reaction from causing the solution to boil-over or damage the vessel.

See also


  1. :Rubidium oxide on WebElements. Accessed in August 2005.
  2. :Rubidium hydroxide on ChemExper. Accessed in September 2005.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Rubidium_hydroxide". A list of authors is available in Wikipedia.
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