Ammonium bromide

Structural formula
${\displaystyle \mathrm {\ {\Biggl [}} }$ ${\displaystyle \mathrm {\ \!\ {\Biggr ]}} }$
General
Surname	Ammonium bromide
other names	Ammonium bromide Bromammonium
Molecular formula	NH 4 Br
Brief description	colorless, odorless, slightly hygroscopic solid
External identifiers / databases
CAS number 12124-97-9 EC number 235-183-8 ECHA InfoCard 100,031,973 PubChem 25514 Wikidata Q413982
properties
Molar mass	97.94 g mol −1
Physical state	firmly
density	2.43 g cm −3 (20 ° C)
Sublimation point	452 ° C
solubility	742 g l −1 (20 ° C) in water soluble in ethanol and acetone
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 319 P: 305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Ammonium bromide , NH ₄ Br, forms hygroscopic cubic crystals that are readily soluble in acetone, ethanol and water. It has a sublimation point of 452 ° C, a density of 2.43 g · cm ⁻³ and a relative molecular mass M _r of 97.942.

synthesis

Ammonium bromide can be produced by the action of hydrogen bromide on ammonia :

${\displaystyle \mathrm {HBr+NH_{3}\longrightarrow NH_{4}Br} }$

The direct reaction of ammonia with bromine in water also gives the salt.

${\displaystyle \mathrm {3\,Br_{2}+8\,NH_{3}\longrightarrow 6\,NH_{4}Br+N_{2}} }$

Another production option is the reaction of ammonia with iron (II) bromide .

${\displaystyle \mathrm {FeBr_{2}+2\,NH_{3}+H_{2}O\longrightarrow 2\,NH_{4}Br+Fe(OH)_{2}} }$

properties

Ammonium bromide forms pale yellow crystals or powders that sublime at 452 ° C under normal pressure . A melting point of 542 ° C. is observed in a closed capillary . The salt is very soluble in water. The solubility increases with increasing temperature. The compound dissolves well in ethanol and acetone .

solubility in water
temperature	in ° C	0	20th	40	60	80	100
solubility	in g / 100 g H 2 O	59.5	74.2	89.8	105	117	135

use

Ammonium bromide is used in the phototechnical industry and in medicine as a sedative . Ammonium bromide can also act as a bromide source in electrochemical bromination.

Individual evidence

1. ↑ ^{a b c d e f} Entry on ammonium bromide in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
2. ↑ ^{a b} entry on ammonium bromide. In: Römpp Online . Georg Thieme Verlag, accessed on July 15, 2014.
3. ↑ ^{a b c d e f g} Yoffe, D .; Frim, R .; Ukeles, SD; Dagani, MJ; Barda, HJ; Benya, TJ; Sanders, DC: Bromine Compounds , in: Ullmanns Enzyklopädie der Technischen Chemie , Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 2013; doi : 10.1002 / 14356007.a04_405.pub2 .
4. ↑ Xiang Yang, Qi-Liang Yang, Xiang-Yang Wang, Hao-Han Xu, Tian-Sheng Mei: Copper-Catalyzed Electrochemical Selective Bromination of 8-Aminoquinoline Amide Using NH ₄ Br as the Brominating Reagent . In: The Journal of Organic Chemistry . tape 85 , no. 5 , March 6, 2020, ISSN  0022-3263 , p. 3497-3507 , doi : 10.1021 / acs.joc.9b03223 .