Octane

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Octane
Skeletal formula of octane
Skeletal formula of octane with all implicit carbons shown, and all explicit hydrogens added
Ball and stick model of octane
Spacefill model of octane
Identifiers
CAS number111-65-9 YesY
PubChem356
ChemSpider349 YesY
EC number203-892-1
UN number1262
DrugBankDB02440
KEGGC01387 YesY
MeSHoctane
ChEBICHEBI:17590 N
ChEMBLCHEMBL134886 YesY
RTECS numberRG8400000
Beilstein Reference1696875
Gmelin Reference82412
3DMetB00281
Jmol-3D imagesImage 1
Properties
Molecular formulaC8H18
Molar mass114.23 g mol−1
AppearanceColorless liquid
OdorOdorless
Density0.703 g cm−3
Melting point−57.1 to −56.6 °C; −70.9 to −69.8 °F; 216.0 to 216.6 K
Boiling point125.1 to 126.1 °C; 257.1 to 258.9 °F; 398.2 to 399.2 K
Solubility in water0.007 mg dm−3 (at 20°C)
log P4.783
Vapor pressure1.47 kPa (at 20.0 °C)
kH29 nmol Pa−1 kg−1
Refractive index (nD)1.398
Viscosity542 μPa s (at 20 °C)
Thermochemistry
Specific
heat capacity
C
255.68 J K−1 mol−1
Std molar
entropy
So298
361.20 J K−1 mol−1
Std enthalpy of
formation
ΔfHo298
−252.1–−248.5 kJ mol−1
Std enthalpy of
combustion
ΔcHo298
−5.53–−5.33 MJ mol−1
Hazards
GHS pictogramsThe flame pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The environment pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal wordDANGER
GHS hazard statementsH225, H304, H315, H336, H410
GHS precautionary statementsP210, P261, P273, P301+310, P331
EU Index601-009-00-8
EU classificationHighly Flammable F Harmful Xn Dangerous for the Environment (Nature) N
R-phrasesR11, R38, R50/53, R65, R67
S-phrases(S2), S16, S29, S33
NFPA 704
Flash point13.0 °C (55.4 °F; 286.1 K)
Explosive limits0.96–6.5%
Related compounds
Related alkanes
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references
 
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For the gasoline rating system, see octane rating. For other uses, see Octane (disambiguation).
Octane
Skeletal formula of octane
Skeletal formula of octane with all implicit carbons shown, and all explicit hydrogens added
Ball and stick model of octane
Spacefill model of octane
Identifiers
CAS number111-65-9 YesY
PubChem356
ChemSpider349 YesY
EC number203-892-1
UN number1262
DrugBankDB02440
KEGGC01387 YesY
MeSHoctane
ChEBICHEBI:17590 N
ChEMBLCHEMBL134886 YesY
RTECS numberRG8400000
Beilstein Reference1696875
Gmelin Reference82412
3DMetB00281
Jmol-3D imagesImage 1
Properties
Molecular formulaC8H18
Molar mass114.23 g mol−1
AppearanceColorless liquid
OdorOdorless
Density0.703 g cm−3
Melting point−57.1 to −56.6 °C; −70.9 to −69.8 °F; 216.0 to 216.6 K
Boiling point125.1 to 126.1 °C; 257.1 to 258.9 °F; 398.2 to 399.2 K
Solubility in water0.007 mg dm−3 (at 20°C)
log P4.783
Vapor pressure1.47 kPa (at 20.0 °C)
kH29 nmol Pa−1 kg−1
Refractive index (nD)1.398
Viscosity542 μPa s (at 20 °C)
Thermochemistry
Specific
heat capacity
C
255.68 J K−1 mol−1
Std molar
entropy
So298
361.20 J K−1 mol−1
Std enthalpy of
formation
ΔfHo298
−252.1–−248.5 kJ mol−1
Std enthalpy of
combustion
ΔcHo298
−5.53–−5.33 MJ mol−1
Hazards
GHS pictogramsThe flame pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The environment pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal wordDANGER
GHS hazard statementsH225, H304, H315, H336, H410
GHS precautionary statementsP210, P261, P273, P301+310, P331
EU Index601-009-00-8
EU classificationHighly Flammable F Harmful Xn Dangerous for the Environment (Nature) N
R-phrasesR11, R38, R50/53, R65, R67
S-phrases(S2), S16, S29, S33
NFPA 704
Flash point13.0 °C (55.4 °F; 286.1 K)
Explosive limits0.96–6.5%
Related compounds
Related alkanes
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Octane is a hydrocarbon and an alkane with the chemical formula C8H18, and the condensed structural formula CH3(CH2)6CH3. Octane has many structural isomers that differ by the amount and location of branching in the carbon chain. One of these isomers, 2,2,4-trimethylpentane (isooctane) is used as one of the standard values in the octane rating scale.

Octane is a component of gasoline (petrol). As with all low molecular weight hydrocarbons, octane is volatile and very flammable.

Use of the term in gasoline[edit]

"Octane" is colloquially used as a short form of "octane rating" (named for the ability of octane's branched-chain isomers, especially isooctane, to reduce engine knock), particularly in the expression "high octane." However, components of gasoline other than isomers of octane can also contribute to a high octane rating, while some isomers of octane can lower it, and n-octane itself has a negative octane rating.[2]

Metaphorical use[edit]

Octane became well known in American popular culture in the mid- and late 1960s, when gasoline companies boasted of "high octane" levels in their gasoline advertisements.

These commercials disappeared by the time of the 1973 Oil Crisis, which spared gasoline companies the need to compete in advertising. "Octane" was rarely cited in non-technical contexts over the next two decades.

The compound adjective "high-octane" is recorded in a figurative sense from 1944.[3] By the mid-1990s, the phrase was commonly being used as an intensifier and has found a place in modern English vernacular.

"Octane" is a slang term for trihexyphenidyl, because of its similarity to its trade name Artane.

Isomers[edit]

Octane has 18 structural isomers (24 including stereoisomers):

References[edit]

  1. ^ "octane - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification and Related Records. Retrieved 6 January 2012. 
  2. ^ eejit's guides – Octane ratings explained
  3. ^ Oxford English Dictionary. 

External links[edit]