Rubidium bromide
Crystal structure | |||||||||||||||||||
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__ Rb + __ Br - | |||||||||||||||||||
Crystal system |
cubic |
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Space group |
Fm 3 m (No. 225) |
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Coordination numbers |
Rb [6], Br [6] |
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General | |||||||||||||||||||
Surname | Rubidium bromide | ||||||||||||||||||
other names |
Rubidium (I) bromide |
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Ratio formula | RbBr | ||||||||||||||||||
Brief description |
white, odorless solid |
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External identifiers / databases | |||||||||||||||||||
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properties | |||||||||||||||||||
Molar mass | 165.37 g mol −1 | ||||||||||||||||||
Physical state |
firmly |
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density |
3.35 g cm −3 |
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Melting point |
682 ° C |
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boiling point |
1340 ° C |
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solubility |
good in water (980 g l −1 at 5 ° C) |
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Refractive index |
1.553 |
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safety instructions | |||||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C |
Rubidium bromide is a chemical compound of rubidium and bromine . It's a white salt .
properties
Solubility of RbBr in Water | ||||||
Temperature in ° C | 0.5 | 5 | 16 | 39.7 | 57.5 | 113.5 |
Solubility in g / l | 896 | 980 | 1048 | 1318.5 | 1524.7 | 2052.1 |
The solubility of rubidium bromide in water is given in the table below. The solubility in acetone is 0.0505 g / kg at 18 ° C and 0.047 g / kg at 37 ° C.
Rubidium bromide crystallizes in the sodium chloride structure . The crystals belong to the space group Fm 3 m (space group no. 225) with the lattice parameter a = 689 pm and four formula units per unit cell . The refractive index of the crystals is n D = 1.5528.
The standard enthalpy of formation of rubidium bromide is Δ f H 0 298 = −389.50 kJ mol −1 , the standard free enthalpy of formation Δ G 0 298 = −378.40 kJ mol −1 , and the standard molar entropy S 0 298 = 108.35 J K −1 mol −1 .
Extraction and presentation
Rubidium bromide can be obtained by reacting rubidium hydroxide and hydrogen bromide :
further reaction options are:
use
Rubidium halides such as rubidium chloride , rubidium bromide and rubidium iodide are used therapeutically as pain relievers and sedatives as well as antidepressants .
Individual evidence
- ↑ a b c d e f data sheet Rubidium bromide, 99.8% (metals basis) from AlfaAesar, accessed on December 7, 2019 ( PDF )(JavaScript required) .
- ↑ a b David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Index of Refraction of Inorganic Crystals, pp. 10-247.
- ↑ a b Aterton Seidell: "Solubilities Of Organic Compounds Vol - I", S. 1429. Full text
- ^ A b Jean D'Ans, Ellen Lax: Paperback for chemists and physicists. 3. Elements, inorganic compounds and materials, minerals, Volume 3. 4. Edition, Springer, 1997, ISBN 978-3-540-60035-0 , p. 684 ( limited preview in the Google book search).
- ↑ a b c R. E. Dickerson, HB Gray, H.-W. Sighting, MY Darensbourg: "Principles of Chemistry", Verlag Walter de Gruyter 1988, ISBN 9783110099690 , p. 976. ( limited preview in Google book search).
- ^ H. Erdmann: Textbook of inorganic chemistry , p. 300, 1900, Verlag F. Vieweg and son.