Rubidium bromide is an inorganic compound with the chemical formula RbBr. It is a salt of hydrogen bromide. It consists of bromide anions Br− and rubidium cations Rb+. It has a NaCl crystal structure, with a lattice constant of 685 picometres.
There are several methods for synthesising rubidium bromide. One involves reacting rubidium hydroxide with hydrobromic acid:
RbOH + HBr → RbBr + H2O
Another method is to neutralize rubidium carbonate with hydrobromic acid:
Rb2CO3 + 2 HBr → 2 RbBr + H2O + CO2
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. It is a white, crystalline solid that is highly soluble in water.
Properties
- Chemical formula: RbBr
- Molar mass|: 165.372 g/mol
- Appearance: white crystalline solid
- Density: 3.350 g/cm3
- Melting point: 693 °C (1,279 °F; 966 K)
- Boiling point: 1,340 °C (2,440 °F; 1,610 K)
- Solubility in water: 98 g/100 mL
Preparation
Rubidium bromide can be prepared by reacting rubidium metal or rubidium hydroxide with hydrobromic acid (HBr): RbOH+HBr→RbBr+H
Natural Occurrence
Rubidium bromide is typically not found in large natural deposits by itself. However, rubidium can be found in trace amounts in certain minerals, such as lepidolite, pollucite, and cesium minerals. It is typically obtained by reacting rubidium compounds (like rubidium chloride) with bromine or bromine-containing substances.
Sources
Rubidium bromide is produced industrially, often as a byproduct of the extraction of rubidium from mineral sources or through the reaction of rubidium hydroxide with hydrobromic acid (HBr).
Uses
- Specialized chemical applications: Used in the preparation of other rubidium compounds.
- In the production of optoelectronic devices: Rubidium bromide crystals are sometimes used in the manufacture of optoelectronic devices.
- In the research industry: Rubidium bromide is used in various laboratory processes, especially in studies involving halide salts.
Safety
- Handling: Like other rubidium salts, rubidium bromide should be handled with care as it can be toxic if ingested or inhaled in large amounts.
- Storage: It should be stored in a dry place, away from moisture, to prevent it from reacting with water.
