Rubidium fluoride
Rubidium fluoride is the fluoride salt of rubidium. It is a white crystalline solid with a cubic crystal structure, similar to common salt. It forms two different hydrates, a sesquihydrate with the stoichiometric composition 2RbF·3H2O and a third hydrate with the composition 3RbF·H2O.
Synthesis
There are several methods for synthesising rubidium fluoride. One involves reacting rubidium hydroxide with hydrofluoric acid:Another method is to neutralize rubidium carbonate with hydrofluoric acid:
Another possible method is to react rubidium hydroxide with ammonium fluoride:
The least used method due to expense of rubidium metal is to react it directly with fluorine gas, as rubidium reacts violently with halogens:
Properties
The enthalpy of solution of rubidium fluoride was determined to be −24.28 kJ/mol.Rubidium fluoride has a purple or magenta red flame test.