Strontium bromide

Crystal structure
	__ Sr 2+ __ Br -
General
Surname	Strontium bromide
other names	Strontium (II) bromide; Strontium dibromide;
Ratio formula	SrBr 2
Brief description	colorless solid
External identifiers / databases
EC number	233-969-5
ECHA InfoCard	100,030,868
PubChem	25302
Wikidata	Q416904
properties
Molar mass	247.44 g mol −1 (pure substance); 355.53 g mol −1 (hexahydrate);
Physical state	firmly
density	4.216 g cm −3 (pure substance); 2.386 g cm −3 (hexahydrate);
Melting point	643 ° C
boiling point	2146 ° C
solubility	easily soluble in water: 1070 g l −1 (25 ° C); soluble in alcohol, insoluble in ether;
safety instructions
GHS labeling of hazardous substances Caution
H and P phrases	H: 315-319-335
	P: 261-305 + 351 + 338
Toxicological data	1 g kg −1 ( LD 50 , rat , iv )
Thermodynamic properties
ΔH f 0	10.12 kJ mol −1
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Strontium bromide is the strontium salt of hydrobromic acid .

Manufacturing

Strontium bromide can be produced from strontium hydroxide and hydrogen bromide by the salt formation reaction .

{\ displaystyle \ mathrm {Sr (OH) _ {2} +2 \ HBr \ longrightarrow SrBr_ {2} +2 \ H_ {2} O}}

Synthesis is also possible from strontium carbonate and hydrogen bromide .

{\ displaystyle \ mathrm {SrCO_ {3} +2 \ HBr \ longrightarrow SrBr_ {2} + H_ {2} O + CO_ {2} \ uparrow}}

properties

Strontium bromide is readily soluble in water; the solubility also increases with increasing temperature: at 0 ° C 852 g, at 25 ° C 1070 g and at 100 ° C 2225 g of strontium bromide dissolve in 1 liter of water. It occurs as the hexahydrate SrBr ₂ · 6 H ₂ O, which is converted at 89 ° C into the dihydrate SrBr ₂ · 2 H ₂ O and finally at 180 ° C into the anhydrate , releasing water of crystallization . Strontium bromide is soluble in ethanol ; crystals with the formula 2 SrBr ₂ · 5 C ₂ H ₅ OH separate from these solutions .

Anhydrous strontium bromide crystallizes in the orthorhombic crystal system in the space group Pnma (space group no. 62) with the lattice parameters a = 920 pm , b = 1142 pm and c = 430 pm as well as four formula units per unit cell . Template: room group / 62

The hexahydrate crystallizes trigonally in the space group P 321 (no.150) or P 312 (no.149) with the lattice parameters a = 823 pm and c = 416 pm. There is a formula unit in the unit cell. Template: room group / 150Template: room group / 149

use

Like other salts of hydrobromic acid ( lithium bromide , potassium bromide ), strontium bromide has a central damping effect . Its use as a sedative is obsolete today.

Individual evidence

^ CRC Handbook of Chemistry and Physics , CRC Press, LLC 2005.

↑ ^a ^b Strontium bromide data sheet from AlfaAesar, accessed on June 7, 2010 ( PDF )(JavaScript required) .

^ ^A ^b ^c Jean D'Ans, Ellen Lax: Pocket book for chemists and physicists. 3. Elements, inorganic compounds and materials, minerals, Volume 3. 4. Edition, Springer, 1997, ISBN 978-3-5406-0035-0 , pp. 742-743 ( limited preview in Google book search).

↑ ^a ^b ^c data sheet Strontium bromide from Sigma-Aldrich , accessed on April 23, 2011 ( PDF ).

↑ ^a ^b ^c ^d ^e Dale L. Perry, Sidney L. Phillips: Handbook of Inorganic Compounds . CRC Press, 1995, ISBN 978-0-8493-8671-8 , p. 387 ( limited preview in Google book search).

↑ Data sheet Strontium bromide, anhydrous (PDF) from Strem, accessed on December 25, 2012.

↑ ^a ^b R. Abegg, F. Auerbach: Handbuch der inorganic Chemie , Vol. 2, Verlag S. Hirzel, 1908. pp. 214-216; Full text

↑ C. Uferer, T. Hückel: Selected standard recipes in the NRF , in: Pharmazeutische Zeitung, edition 11/2000.

[1] CRC Handbook of Chemistry and Physics , CRC Press, LLC 2005.