Mercury(II) bromide

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Mercury(II) bromide
Mercury(II) bromide
Identifiers
CAS number 7789-47-1 YesY
PubChem 24612
RTECS number OV7415000
Properties
Molecular formula HgBr2
Molar mass 360.41 g/mol
Appearance white solid
Density 6.03 g/cm³, solid
Melting point 237 °C (459 °F; 510 K)
Boiling point 322 °C (612 °F; 595 K)
Solubility in water soluble
Solubility very slightly soluble in ether
Structure
Coordination
geometry
rhombic
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
Flammability code 0: Will not burn. E.g., water Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
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
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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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.

Preparation[edit]

Mercury(II) bromide can be manufactured by: adding potassium bromide to a solution of mercuric salt and crystallizing; by precipitation using a mercury(II) nitrate and sodium bromide solution; by dissolving mercury(II) oxide in hydrobromic acid.

Reactions[edit]

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[edit]

  1. ^ Horton, Derek (2004), Advances in Carbohydrate Chemistry and Biochemistry, Amsterdam: Elseveir Academic Press, p. 76, ISBN 0-12-007259-9, retrieved 2008-05-29 
  2. ^ Stick, Robert V. (2001), Carbohydrates: The Sweet Molecules of Life, San Diego: Academic Press, p. 125, ISBN 0-12-670960-2, retrieved 2008-05-29 
  3. ^ Pederson, Ole (2006), Pharmaceutical Chemical Analysis, Boca Raton, FL: CRC Press, p. 107, ISBN 0-8493-1978-1, retrieved 2008-05-29 
  4. ^ Odegaard, Nancy; Sadongei, Alyce (2005), Old Poisons, New Problems, Rowman Altamira, p. 58, ISBN 0-7591-0515-4, retrieved 2008-05-29 
  5. ^ Townsend, Timothy G.; Solo-Gabriele, Helena (2006), Environmental Impacts of Treated Wood, Boca Raton, FL: CRC Press, p. 339, ISBN 0-8493-6495-7, retrieved 2008-05-29 
  6. ^ Bretherick, L.; Urben, P. G.; Pitt, Martin John (1999), Bretherick's Handbook of Reactive Chemical Hazards, Elseveir Academic Press, p. 110, ISBN 0-7506-3605-X, retrieved 2008-05-29 
  7. ^ Bretherick, L.; Urben, P. G.; Pitt, Martin John (1999), Bretherick's Handbook of Reactive Chemical Hazards, Elseveir Academic Press, p. 1276, ISBN 0-7506-3605-X, retrieved 2008-05-29