Radium bromide

Crystal structure
	__ Ra 2+ __ Br -
General
Surname	Radium bromide
Ratio formula	RaBr 2
Brief description	white solid
External identifiers / databases
EC number	233-086-5
ECHA InfoCard	100.030.066
Wikidata	Q2653992
properties
Molar mass	385.83 g mol −1
Physical state	firmly
density	5.78 g cm −3
Melting point	728 ° C
solubility	very easily soluble in water (706 g l −1 at 20 ° C); insoluble in a 4: 1 (v / v) mixture of 47% HBr and methanol ;
Hazard and safety information
	; Radioactive
GHS hazard labeling ; no classification available
GHS hazard labeling ; no classification available
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Radium bromide is a white solid that glows by itself in the dark . Over time, radium bromide turns yellowish due to radiolysis .

Extraction and presentation

Anhydrous radium bromide is produced by reacting the chloride with gaseous hydrogen bromide for several hours in a red heat . The dihydrate RaBr ₂ · 2 H ₂ O of radium bromide is obtained by dissolving radium carbonate in hydrobromic acid and subsequent crystallization.

{\ displaystyle \ mathrm {RaCO_ {3} +2 \ HBr + H_ {2} O \ longrightarrow RaBr_ {2} \ cdot \ 2 \ H_ {2} O + CO_ {2} \ uparrow}}

properties

Radium bromide crystallizes out as a dihydrate from aqueous solution, which is isomorphic with barium bromide BaBr ₂ · 2H ₂ O. The dihydrate can be dehydrated by passing dry air at 200 ° C over it. The freshly crystallized salt is colorless, but turns yellow over time through radiolysis through alpha radiation . The helium created in the crystals can cause the crystals to burst.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Kirby, HW and Salutsky, Murrell L. (1964) The Radiochemistry of Radium , Subcommittee on Radiochemistry, National Academy of Sciences, accessed February 28, 2017.
^ William M. Haynes: CRC Handbook of Chemistry and Physics, 97th Edition . CRC Press, 2016, ISBN 978-1-4987-5429-3 , pp. 100 ( limited preview in Google Book search).
↑ The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling. With regard to other hazards, this substance has either not yet been classified or a reliable and citable source has not yet been found.
↑ Gmelin's Handbook of Inorganic Chemistry: Radium, System Number 31, Eighth Edition, Verlag Chemie GmbH, Berlin 1927, pages 61-62.

[Kirby-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Kirby, HW and Salutsky, Murrell L. (1964) The Radiochemistry of Radium , Subcommittee on Radiochemistry, National Academy of Sciences, accessed February 28, 2017.

[William_M._Haynes-2] William M. Haynes: CRC Handbook of Chemistry and Physics, 97th Edition . CRC Press, 2016, ISBN 978-1-4987-5429-3 , pp. 100 ( limited preview in Google Book search).

[NV-3] The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling. With regard to other hazards, this substance has either not yet been classified or a reliable and citable source has not yet been found.

[Gmelin-4] Gmelin's Handbook of Inorganic Chemistry: Radium, System Number 31, Eighth Edition, Verlag Chemie GmbH, Berlin 1927, pages 61-62.