Zinc bromide

Crystal structure
__ Zn 2+      __ Br -
General
Surname	Zinc bromide
other names	Zinc (II) bromide
Ratio formula	ZnBr 2
Brief description	white, almost odorless solid
External identifiers / databases
CAS number 7699-45-8 (anhydrous) 18921-13-6 (dihydrate) PubChem 24375 Wikidata Q204679
properties
Molar mass	225.18 g · mol -1
Physical state	firmly
density	4.2 g cm −3 (20 ° C)
Melting point	394 ° C
boiling point	697 ° C
solubility	very good in water (4470 g l −1 at 20 ° C) soluble in ethanol and ether
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 302-314-317-411 P: 273-280-305 + 351 + 338-310
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Zinc bromide is a chemical compound that is mainly used in electrolysis and in the oil industry. It is the bromide of zinc .

Extraction and presentation

Zinc bromide can be obtained by reacting zinc with bromine .

${\displaystyle \mathrm {Br_{2}+Zn\longrightarrow ZnBr_{2}} }$

Further possibilities are the reaction of barium bromide with zinc sulphate (which also forms barium sulphate ) or the reaction of hydrogen bromide with zinc:

${\displaystyle \mathrm {BaBr_{2}+ZnSO_{4}\longrightarrow BaSO_{4}+ZnBr_{2}} }$

${\displaystyle \mathrm {Zn+2\ HBr\longrightarrow ZnBr_{2}+H_{2}} }$

Chemical properties

Zinc bromide is a white, almost odorless, very hygroscopic solid and a Lewis acid . The dihydrate ZnBr ₂ · 2H ₂ O crystallizes out from aqueous solution below 37 ° C. The real structure of the dihydrate is Zn (H ₂ O) ₆ Zn ₂ Br ₆ , with the two zinc atoms in the Zn ₂ Br ₆ ²⁻ anion being linked via bromine atoms.

use

Zinc bromide is often used in school experiments to demonstrate the chemical principles of electrolysis or of batteries or accumulators . It is also used as an additive in fluxes for soldering and for the production of zinc organic compounds ( zinc organyls ) by electrolysis. In medicine it can be used as a sedative .

Most of the zinc bromide produced is used in deep-sea oil drilling as a component of the displacement and reaction fluid.

safety instructions

Zinc bromide has a caustic and corrosive effect on metals.

Individual evidence

1. ↑ ^{a b c d e f g} Zinc bromide data sheet (PDF) from Merck , accessed April 25, 2011.
2. ↑ ^{a b} Georg Brauer (Ed.), With the collaboration of Marianne Baudler u a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1025.
3. ↑ ^{a b} Entry on zinc bromide in the GESTIS substance database of the IFA , accessed on July 23, 2016(JavaScript required) .
4. ↑ Pradyot Patnaik, 2003, Handbook of Inorganic Chemicals, McGraw-Hill Professional, ISBN 0070494398 .
5. ↑ 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 .
6. ↑ Duhlev, R .; Brown, ID; Faggiani, R .: Zinc bromide dihydrate ZnBr ₂ · 2H ₂ O: a double-salt structure in Acta Cryst. C, Cryst. Struct. Commun. 44 (1988), 1696-1698, doi : 10.1107 / S0108270188005876 , pdf .
7. ↑ Martin Winter, Jürgen 0. Besenhard: Rechargeable batteries ( Memento of the original from May 17, 2013 in the Internet Archive ) Info: The  archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF file; 8.4 MB) . Chemistry in Our Time, 33 (5), 1999.
8. ↑ data sheet at chemicalland21.com
9. ↑ Viktorija Rjabova: Influence of the structure of CH-acidic nitriles on the electrochemical synthesis of organometallic complexes of copper and zinc . Dissertation, 2001.