Rubidium bromide is the
bromide
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant ...
of
rubidium. It has a
NaCl
Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g/ ...
crystal structure, with a lattice constant of 685 picometres.
There are several methods for synthesising rubidium bromide. One involves reacting
rubidium hydroxide
Rubidium hydroxide is the inorganic compound with the formula RbOH. It consists of rubidium cations and an equal number of hydroxide anions. It is a colorless solid that is commercially available as aqueous solutions from a few suppliers. Like ot ...
with
hydrobromic acid
Hydrobromic acid is a strong acid formed by dissolving the diatomic molecule hydrogen bromide (HBr) in water. "Constant boiling" hydrobromic acid is an aqueous solution that distills at and contains 47.6% HBr by mass, which is 8.77 mol/L. ...
:
:RbOH + HBr → RbBr + H
2O
Another method is to neutralize
rubidium carbonate with hydrobromic acid:
:Rb
2CO
3 + 2 HBr → 2 RbBr + H
2O + CO
2
Rubidium metal would react directly with bromine to form RbBr, but this is not a sensible production method, since rubidium metal is substantially more expensive than the carbonate or hydroxide; moreover, the reaction would be explosive.
References
WebElements URL accessed March 1, 2006.
Rubidium compounds
Bromides
Metal halides
Alkali metal bromides
Rock salt crystal structure
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