Rubidium bromide

Crystal structure
__ Rb +      __ Br -
Crystal system	cubic
Space group	Fm 3 m (No. 225)
Coordination numbers	Rb [6], Br [6]
General
Surname	Rubidium bromide
other names	Rubidium (I) bromide
Ratio formula	RbBr
Brief description	white, odorless solid
External identifiers / databases
CAS number 7789-39-1 EC number 232-162-5 ECHA InfoCard 100.029.238 PubChem 4670918 ChemSpider 74217 Wikidata Q421120
properties
Molar mass	165.37 g mol −1
Physical state	firmly
density	3.35 g cm −3
Melting point	682 ° C
boiling point	1340 ° C
solubility	good in water (980 g l −1 at 5 ° C)
Refractive index	1.553
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
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 :

${\displaystyle \mathrm {RbOH+HBr\longrightarrow RbBr+H_{2}O} }$

further reaction options are:

${\displaystyle \mathrm {2\ Rb+Br_{2}\longrightarrow 2\ RbBr} }$

${\displaystyle \mathrm {Rb_{2}CO_{3}+2\ HBr\longrightarrow 2\ RbBr+H_{2}O+CO_{2}} }$

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

1. ↑ ^{a b c d e f} data sheet Rubidium bromide, 99.8% (metals basis) from AlfaAesar, accessed on December 7, 2019 ( PDF )(JavaScript required) .
2. ↑ ^{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.
3. ↑ ^{a b} Aterton Seidell: "Solubilities Of Organic Compounds Vol - I", S. 1429. Full text
4. ^ ^{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).
5. ↑ ^{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).
6. ^ H. Erdmann: Textbook of inorganic chemistry , p. 300, 1900, Verlag F. Vieweg and son.