Lead(II) bromide
Lead(II) bromide is the inorganic compound with the formula PbBr2. It is a white powder. It is produced in the burning of typical leaded gasolines.[3]
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| Names | |
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| IUPAC name
Lead(II) bromide | |
| Other names
Lead dibromide | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.030.065  |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| PbBr2 | |
| Molar mass | 367.01 g/mol |
| Appearance | white powder |
| Density | 6.66 g/cm3 [1] |
| Melting point | 370.6 °C (699.1 °F; 643.8 K) |
| Boiling point | 916 °C (1,681 °F; 1,189 K) (vaporizes) |
| 0.455 g/100 mL (0 °C) 0.973 g/100 mL (20 °C)[2] 4.41 g/100 mL (100 °C) | |
Solubility product (Ksp) |
1.86 x 10−5 (20 °C) |
| Solubility | insoluble in alcohol; soluble in ammonia, alkali, KBr, NaBr |
| −90.6·10−6 cm3/mol | |
| Hazards | |
EU classification (DSD) (outdated) |
Repr. Cat. 1/3 Harmful (Xn) Dangerous for the environment (N) |
| R-phrases (outdated) | R61, R20/22, R33, R62, R50/53 |
| S-phrases (outdated) | S53, S45, S60, S61 |
| NFPA 704 (fire diamond) | |
| Related compounds | |
Other anions |
Lead(II) fluoride, Lead(II) chloride, Lead(II) iodide |
Other cations |
Thallium(I) bromide, Tin(II) bromide Bismuth bromide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
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| Infobox references | |
Preparation and properties
It is typically prepared from treating solutions of lead salts (e.g., (lead(II) nitrate) with bromide salts. This process exploits its low solubility in water - only 0.455 g dissolves in 100 g of water at 0 °C. It is about ten times more soluble in boiling water.[4]
Lead bromide was prevalent in the environment as the result of the use of leaded gasoline. Tetraethyl lead was once widely used to improve the combustion properties of gasoline. To prevent the resulting lead oxides from fouling the engine, gasoline was treated with an organobromine compound that converted lead oxides into the more volatile lead bromide, which was then exhausted from the engine into the environment.[3]
Safety
Like other compounds containing lead, lead dibromide is categorized as probably carcinogenic to humans (Category 2A), by the International Agency for Research on Cancer (IARC). Its release into the environment as a product of leaded gasoline was highly controversial.
References
- Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3.
- NIST-data review 1980
- Michael J. Dagani, Henry J. Barda, Theodore J. Benya, David C. Sanders "Bromine Compounds" in Ullmann's Encyclopedia of Industrial Chemistry" Wiley-VCH, Weinheim, 2000.doi:10.1002/14356007.a04_405
- Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.