Benzene

This article is about the chemical compound. For other uses, see Benzene (disambiguation).
Not to be confused with Petroleum benzine.
Benzene
Benzene molecule
Space-filling model
Skeletal formula detail of benzene.
Skeletal formula detail of benzene.
Geometry
Benzene ball-and-stick model
Benzene ball-and-stick model
Ball and stick model
Sample of benzene
Benzene at room temperature
Names
Preferred IUPAC name
Benzene[1]
Other names
Benzol (historic/German)
Cyclohexa-1,3,5-triene; 1,3,5-Cyclohexatriene (theoretical resonance isomers)
[6]Annulene (not recommended[1])
Phene (historic)
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.000.685 Edit this at Wikidata
EC Number
  • 200-753-7
KEGG
RTECS number
  • CY1400000
UNII
  • InChI=1S/C6H6/c1-2-4-6-5-3-1/h1-6H checkY
    Key: UHOVQNZJYSORNB-UHFFFAOYSA-N checkY
  • c1ccccc1
Properties
C6H6
Molar mass 78.114 g·mol−1
Appearance Colorless liquid
Odor sweet aromatic
Density 0.8765(20) g/cm3[2]
Melting point 5.53 °C (41.95 °F; 278.68 K)
Boiling point 80.1 °C (176.2 °F; 353.2 K)
1.53 g/L (0 °C)
1.81 g/L (9 °C)
1.79 g/L (15 °C)[3][4][5]
1.84 g/L (30 °C)
2.26 g/L (61 °C)
3.94 g/L (100 °C)
21.7 g/kg (200 °C, 6.5 MPa)
17.8 g/kg (200 °C, 40 MPa)[6]
Solubility Soluble in alcohol, CHCl3, CCl4, diethyl ether, acetone, acetic acid[6]
Solubility in ethanediol 5.83 g/100 g (20 °C)
6.61 g/100 g (40 °C)
7.61 g/100 g (60 °C)[6]
Solubility in ethanol 20 °C, solution in ethanol:
1.2 mL/L (20% v/v)[7]
Solubility in acetone 20 °C, solution in acetone:
7.69 mL/L (38.46% v/v)
49.4 mL/L (62.5% v/v)[7]
Solubility in diethylene glycol 52 g/100 g (20 °C)[6]
log P 2.13
Vapor pressure 12.7 kPa (25 °C)
24.4 kPa (40 °C)
181 kPa (100 °C)[8]
Conjugate acid Benzenium[9]
Conjugate base Benzenide[10]
UV-vis (λmax) 255 nm
−54.8·10−6 cm3/mol
1.5011 (20 °C)
1.4948 (30 °C)[6]
Viscosity 0.7528 cP (10 °C)
0.6076 cP (25 °C)
0.4965 cP (40 °C)
0.3075 cP (80 °C)
Structure
Trigonal planar
0 D
Thermochemistry
134.8 J/mol·K
173.26 J/mol·K[8]
48.7 kJ/mol
-3267.6 kJ/mol[8]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 potential occupational carcinogen, flammable
GHS labelling:
GHS02: FlammableGHS06: ToxicGHS07: Exclamation markGHS08: Health hazardGHS09: Environmental hazard[11]
Danger
H225, H302, H304, H305, H315, H319, H340, H350, H372, H410[11]
P201, P210, P301+P310, P305+P351+P338, P308+P313, P331[11]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
3
0
Flash point −11.63 °C (11.07 °F; 261.52 K)
497.78 °C (928.00 °F; 770.93 K)
Explosive limits 1.2–7.8%
Lethal dose or concentration (LD, LC):
930 mg/kg (rat, oral)[13]
44,000 ppm (rabbit, 30 min)
44,923 ppm (dog)
52,308 ppm (cat)
20,000 ppm (human, 5 min)[14]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 1 ppm, ST 5 ppm[12]
REL (Recommended)
 Ca TWA 0.1 ppm ST 1 ppm[12]
IDLH (Immediate danger)
 500 ppm[12]
Safety data sheet (SDS) HMDB
Related compounds
Related compounds
 Toluene
Borazine
Supplementary data page
Benzene (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon.

Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline. It is used primarily as a precursor to the manufacture of chemicals with more complex structures, such as ethylbenzene and cumene, of which billions of kilograms are produced annually. Although benzene is a major industrial chemical, it finds limited use in consumer items because of its toxicity. Benzene is a volatile organic compound.[15]

Benzene is classified as a carcinogen. Its particular effects on human health, such as the long-term results of accidental exposure, have been reported on by news organizations such as The New York Times. For instance, a 2022 article stated that benzene contamination in the Boston metropolitan area caused hazardous conditions in multiple places, with the publication noting that the compound may eventually cause leukemia in some individuals.[16]

  1. ^ a b Favre, Henri A.; Powell, Warren H. (2014). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. pp. 10, 22, 204, 494, 577. doi:10.1039/9781849733069. ISBN 978-0-85404-182-4.
  2. ^ Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
  3. ^ Arnold, D.; Plank, C.; Erickson, E.; Pike, F. (1958). "Solubility of Benzene in Water". Industrial & Engineering Chemistry Chemical & Engineering Data Series. 3 (2): 253–256. doi:10.1021/i460004a016.
  4. ^ Breslow, R.; Guo, T. (1990). "Surface tension measurements show that chaotropic salting-in denaturants are not just water-structure breakers". Proceedings of the National Academy of Sciences of the United States of America. 87 (1): 167–9. Bibcode:1990PNAS...87..167B. doi:10.1073/pnas.87.1.167. PMC 53221. PMID 2153285.
  5. ^ Coker, A. Kayode; Ludwig, Ernest E. (2007). Ludwig's Applied Process Design for Chemical And Petrochemical Plants. Vol. 1. Elsevier. p. 114. ISBN 978-0-7506-7766-0. Archived from the original on 2016-03-12. Retrieved 2012-05-31.
  6. ^ a b c d e "Benzol". Archived from the original on 2014-05-29. Retrieved 2014-05-29.
  7. ^ a b Atherton Seidell; William F. Linke (1952). Solubilities of Inorganic and Organic Compounds: A Compilation of Solubility Data from the Periodical Literature. Supplement. Van Nostrand. Archived from the original on 2020-03-11. Retrieved 2015-06-27.
  8. ^ a b c Benzene in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD) (retrieved 2014-05-29)
  9. ^ "Benzenium (CID 12533897". PubChem. February 8, 2007. Retrieved September 18, 2022.
  10. ^ "Benzenide (CID 5150480)". PubChem. June 24, 2005. Retrieved September 18, 2022.
  11. ^ a b c Sigma-Aldrich Co., Benzene Archived 2016-12-01 at the Wayback Machine. Retrieved on 2014-05-29.
  12. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0049". National Institute for Occupational Safety and Health (NIOSH).
  13. ^ MSDS
  14. ^ "Benzene". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  15. ^ "Benzene fact sheet". CDC. 2 September 2021. Retrieved 16 Aug 2023.
  16. ^ Shao, Elena (28 June 2022). "Gas Piped into Homes Contains Benzene and Other Risky Chemicals, Study Finds". The New York Times.