Mercury(II) bromide

Mercury(II) bromide
IUPAC name Mercury(II) bromide
Other names Mercuric bromide
Identifiers
CAS number	7789-47-1 Y
RTECS number	OV7415000
Properties
Molecular formula	HgBr2
Molar mass	360.41 g/mol
Appearance	white solid
Density	6.03 g/cm³, solid
Melting point	236 °C
Boiling point	322 °C
Hazards
EU Index	080-002-00-6
EU classification	Very toxic (T+) Dangerous for the environment (N)
R-phrases	R26/27/28, R33, R50/53
S-phrases	(S1/2), S13, S28, S45, S60, S61
NFPA 704	0 3 0
Flash point	Non-flammable
Related compounds
Other anions	Mercury(II) fluoride Mercury(II) chloride Mercury(II) iodide
Other cations	Zinc bromide Cadmium bromide Mercury(I) bromide
Y bromide (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Mercury(II) bromide or mercuric bromide is the chemical compound composed of mercury and bromine with the formula HgBr₂. This white crystalline solid is a laboratory reagent. Like mercury(II) chloride, it is extremely toxic.

Reactions

Mercury(II) bromide is used as a reagent in the Koenigs–Knorr reaction, which forms glycoside linkages on carbohydrates.^[1][2]

It is also used to test for the presence of arsenic, as recommended by the Pharmacopoeia.^[3] The arsenic in the sample is first converted to arsine gas by treatment with hydrogen. Arsine reacts with mercury(II) bromide:^[4]

AsH₃ + 3HgBr₂ → As(HgBr)₃ + 3HBr

The white mercury(II) bromide will turn yellow, brown, or black if arsenic is present in the sample.^[5]

Mercury(II) bromide reacts violently with elemental indium at high temperatures^[6] and, when exposed to potassium, can form shock-sensitive explosive mixtures.^[7]

References

1. ^ Horton, Derek (2004), Advances in Carbohydrate Chemistry and Biochemistry, Amsterdam: Elseveir Academic Press, pp. 76, ISBN 0120072599, http://books.google.com/?id=E22gW9CbU_0C&pg=PA76&dq=%22mercury(II)+bromide%22, retrieved 2008-05-29 
2. ^ Stick, Robert V. (2001), Carbohydrates: The Sweet Molecules of Life, San Diego: Academic Press, pp. 125, ISBN 0126709602, http://books.google.com/?id=-MtjsUMB6ogC&pg=PA125&dq=%22mercury(II)+bromide%22, retrieved 2008-05-29 
3. ^ Pederson, Ole (2006), Pharmaceutical Chemical Analysis, Boca Raton, FL: CRC Press, pp. 107, ISBN 0849319781, http://books.google.com/?id=R7ZxXS5DZj8C&pg=PT125&dq=%22mercury(II)+bromide%22, retrieved 2008-05-29 
4. ^ Odegaard, Nancy; Sadongei, Alyce (2005), Old Poisons, New Problems, Rowman Altamira, pp. 58, ISBN 0759105154, http://books.google.com/?id=QLU0SVlruCMC&pg=PA58&dq=%22mercury(II)+bromide%22, retrieved 2008-05-29 
5. ^ Townsend, Timothy G.; Solo-Gabriele, Helena (2006), Environmental Impacts of Treated Wood, Boca Raton, FL: CRC Press, pp. 339, ISBN 0849364957, http://books.google.com/?id=ENJL1UMdGTUC&pg=PT361&dq=%22mercury(II)+bromide%22, retrieved 2008-05-29 
6. ^ Bretherick, L.; Urben, P. G.; Pitt, Martin John (1999), Bretherick's Handbook of Reactive Chemical Hazards, Elseveir Academic Press, pp. 110, ISBN 075063605X, http://books.google.com/?id=UOxbX8q6DXsC&pg=PA1726&dq=%22mercury(II)+bromide%22, retrieved 2008-05-29 
7. ^ Bretherick, L.; Urben, P. G.; Pitt, Martin John (1999), Bretherick's Handbook of Reactive Chemical Hazards, Elseveir Academic Press, pp. 1276, ISBN 075063605X, http://books.google.com/?id=UOxbX8q6DXsC&pg=PA1726&dq=%22mercury(II)+bromide%22, retrieved 2008-05-29