Benzene
Space-filling model
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Benzene at room temperature
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| Names | |||
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| 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 | |||
CAS Number
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3D model (JSmol)
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| ChEBI | |||
| ChEMBL | |||
| ChemSpider | |||
| ECHA InfoCard | 100.000.685 | ||
| EC Number |
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| KEGG | |||
PubChem CID
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| RTECS number |
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| UNII | |||
CompTox Dashboard (EPA)
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InChI
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SMILES
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| Properties | |||
Chemical formula
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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) | ||
Solubility in water
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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 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)[7] | ||
| Conjugate acid | Benzenium[8] | ||
| Conjugate base | Benzenide[9] | ||
| UV-vis (λmax) | 255 nm | ||
Magnetic susceptibility (χ)
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−54.8·10−6 cm3/mol | ||
Refractive index (nD)
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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 | |||
Molecular shape
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Trigonal planar | ||
Dipole moment
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0 D | ||
| Thermochemistry | |||
Heat capacity (C)
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134.8 J/mol·K | ||
Std molar
entropy (S⦵298) |
173.26 J/mol·K[7] | ||
Std enthalpy of
formation (ΔfH⦵298) |
48.7 kJ/mol | ||
Std enthalpy of
combustion (ΔcH⦵298) |
−3267.6 kJ/mol[7] | ||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards
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potential occupational carcinogen, flammable | ||
| GHS labelling: | |||
Pictograms
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[10] | ||
Signal word
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Danger | ||
Hazard statements
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H225, H302, H304, H305, H315, H319, H340, H350, H372, H410[10] | ||
Precautionary statements
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P201, P210, P301+P310, P305+P351+P338, P308+P313, P331[10] | ||
| NFPA 704 (fire diamond) | |||
| Flash point | −11.63 °C (11.07 °F; 261.52 K) | ||
Autoignition
temperature |
497.78 °C (928.00 °F; 770.93 K) | ||
| Explosive limits | 1.2–7.8% | ||
| Lethal dose or concentration (LD, LC): | |||
LD50 (median dose)
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930 mg/kg (rat, oral)[12] | ||
LCLo (lowest published)
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44,000 ppm (rabbit, 30 min) 44,923 ppm (dog) 52,308 ppm (cat) 20,000 ppm (human, 5 min)[13] | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible)
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TWA 1 ppm, ST 5 ppm[11] | ||
REL (Recommended)
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Ca TWA 0.1 ppm ST 1 ppm[11] | ||
IDLH (Immediate danger)
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500 ppm[11] | ||
| Safety data sheet (SDS) | HMDB | ||
| Related compounds | |||
Related compounds
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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).
Infobox references
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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 and satisfying Hückel's rule, 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.[14]
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.[15]
- ^ 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.
- ^ Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton, Florida: CRC Press. ISBN 0-8493-0486-5.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ a b c d e "Benzol". Archived from the original on 2014-05-29. Retrieved 2014-05-29.
- ^ 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)
- ^ "Benzenium (CID 12533897". PubChem. February 8, 2007. Retrieved September 18, 2022.
- ^ "Benzenide (CID 5150480)". PubChem. June 24, 2005. Retrieved September 18, 2022.
- ^ a b c Sigma-Aldrich Co., Benzene Archived 2016-12-01 at the Wayback Machine. Retrieved on 2014-05-29.
- ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0049". National Institute for Occupational Safety and Health (NIOSH).
- ^ MSDS
- ^ "Benzene". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ "Benzene fact sheet". CDC. 2 September 2021. Retrieved 16 Aug 2023.
- ^ Shao, Elena (28 June 2022). "Gas Piped into Homes Contains Benzene and Other Risky Chemicals, Study Finds". The New York Times.