| IUPAC name
|Molar mass||102.475 g/mol|
|Appearance||Colorless hygroscopic solid|
|Density||1.74 g/cm3 (at 25 °C)|
|Melting point||301 °C (574 °F; 574 K)|
|Boiling point||1,390 °C (2,530 °F; 1,660 K)|
|100 g/100 ml (15 °C)|
|Solubility|| Reacts with acids|
Soluble in ethanol, methanol
Insoluble in anh. ammonia, diethyl ether, THF
|Vapor pressure||~0 mmHg|
Std enthalpy of
|Safety data sheet||Sigma-Aldrich|
| Lithium hydroxide|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Rubidium hydroxide is a strong base with the formula RbOH.
Rubidium hydroxide is hygroscopic and will rapidly absorb carbon dioxide from air to form rubidium carbonate and bicarbonate.
Rubidium hydroxide is a white hygroscopic solid, which is very soluble in water.
Rubidium hydroxide is commercially available from a certain number of chemical suppliers in form of 50% or 99% aqueous solution.
Rubidium hydroxide can be synthesized by carefully adding rubidium oxide into water:
- Rb2O + H2O → 2 RbOH
Boiling a solution of rubidium carbonate with calcium hydroxide will also yield rubidium hydroxide.
- Make rubidium salts
- Make rubidium metal
Rubidium hydroxide is highly caustic and protection must be worn at all times when handling the compound. Dissolving this compound in water will release a large amount of heat, as well as particulates of RbOH solution, which is corrosive.
Rubidium, like sodium and potassium, almost always has +1 oxidation state when dissolved in water, even in biological contexts. The human body tends to treat Rb+ ions as if they were potassium ions, and therefore concentrates rubidium in the body's intracellular fluid (i.e., inside cells). The ions are not particularly toxic; a 70 kg person contains on average 0.36 g of rubidium, and an increase in this value by 50 to 100 times did not show negative effects in test persons. The biological half-life of rubidium in humans measures 31–46 days.
Rubidium hydroxide should be kept in air-tight containers, away from acids.
Since rubidium is expensive, it's best to recycle this compound.