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Octane

Names
Systematic IUPAC name Octane
Other names n-Octane
Identifiers
CAS Number	111-65-9
3D model (JSmol)	Interactive image
3DMet	B00281
Beilstein Reference	1696875
ChEBI	CHEBI:17590
ChEMBL	ChEMBL134886
ChemSpider	349
DrugBank	DB02440
ECHA InfoCard	100.003.539
EC Number	203-892-1
Gmelin Reference	82412
KEGG	C01387
MeSH	octane
PubChem CID	356
RTECS number	RG8400000
UNII	X1RV0B2FJV
UN number	1262
CompTox Dashboard (EPA)	DTXSID0026882
InChI InChI=1S/C8H18/c1-3-5-7-8-6-4-2/h3-8H2,1-2H3Key: TVMXDCGIABBOFY-UHFFFAOYSA-N
SMILES CCCCCCCC
Properties
Chemical formula	CH3(CH2)6CH3
Molar mass	114.232 g·mol
Appearance	Colourless liquid
Odor	Gasoline-like
Density	0.703 g/cm
Melting point	−57.1 to −56.6 °C; −70.9 to −69.8 °F; 216.0 to 216.6 K
Boiling point	125.1 to 126.1 °C; 257.1 to 258.9 °F; 398.2 to 399.2 K
Solubility in water	0.007 mg/dm (at 20 °C)
log P	4.783
Vapor pressure	1.47 kPa (at 20.0 °C)
Henry's law constant (kH)	29 nmol/(Pa·kg)
Conjugate acid	Octonium
Magnetic susceptibility (χ)	−96.63·10 cm/mol
Refractive index (nD)	1.398
Viscosity	0.509 mPa·s (25 °C) 0.542 mPa·s (20 °C)
Thermochemistry
Heat capacity (C)	255.68 J/(K·mol)
Std molar entropy (S298)	361.20 J/(K·mol)
Std enthalpy of formation (ΔfH298)	−252.1 to −248.5 kJ/mol
Std enthalpy of combustion (ΔcH298)	−5.53 to −5.33 MJ/mol
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H304, H315, H336, H410
Precautionary statements	P210, P261, P273, P301+P310, P331
NFPA 704 (fire diamond)	1 3 0
Flash point	13.0 °C (55.4 °F; 286.1 K)
Autoignition temperature	220.0 °C (428.0 °F; 493.1 K)
Explosive limits	0.96 – 6.5%
Lethal dose or concentration (LD, LC):
LDLo (lowest published)	428 mg/kg (mouse, intravenous)
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 500 ppm (2350 mg/m)
REL (Recommended)	TWA 75 ppm (350 mg/m) C 385 ppm (1800 mg/m)
IDLH (Immediate danger)	1000 ppm
Related compounds
Related alkanes	Methane Ethane Propane Butane Pentane Hexane Heptane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). N verify (what is  ?) 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 location of branching in the carbon chain. One of these isomers, 2,2,4-trimethylpentane (commonly called iso-octane), is used as one of the standard values in the octane rating scale.

Octane is a component of gasoline and petroleum. Under standard temperature and pressure, octane is an odorless, colorless liquid. Like other short-chained alkanes with a low molecular weight, it is volatile, flammable, and toxic. Octane is 1.2 to 2 times more toxic than heptane.

Isomers

N-octane has 23 constitutional isomers. 8 of these isomers have one stereocenter; 3 of them have two stereocenters.

Achiral Isomers:

• 2-Methylheptane
• 4-Methylheptane
• 3-Ethylhexane
• 2,2-Dimethylhexane
• 2,5-Dimethylhexane
• (meso)-3,4-Dimethylhexane
• 3,3-Dimethylhexane
• 3-Ethyl-2-methylpentane
• 3-Ethyl-3-methylpentane
• 2,2,4-Trimethylpentane (i.e. iso-octane)
• 2,3,3-Trimethylpentane
• 2,3,4-Trimethylpentane
• 2,2,3,3-Tetramethylbutane

Chiral Isomers:

• (3R)-3-Methylheptane
• (3S)-3-Methylheptane
• (3R)-2,3-Dimethylhexane
• (3S)-2,3-Dimethylhexane
• (4R)-2,4-Dimethylhexane
• (4S)-2,4-Dimethylhexane
• (3R,4R)-3,4-Dimethylhexane
• (3S,4S)-3,4-Dimethylhexane
• (3R)-2,2,3-Trimethylpentane
• (3S)-2,2,3-Trimethylpentane

Production and Use

In petrochemistry, octanes are not typically differentiated or purified as specific compounds. Octanes are components of particular boiling fractions.

A common route to such fractions is the alkylation reaction between iso-butane and 1-butene, which forms iso-octane.

Octane is commonly used as a solvent in paints and adhesives.

References

1. "octane - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification and Related Records. Retrieved 6 January 2012.
2. ^ NIOSH Pocket Guide to Chemical Hazards. "#0470". National Institute for Occupational Safety and Health (NIOSH).
3. Dymond, J. H.; Oye, H. A. (1994). "Viscosity of Selected Liquid n-Alkanes". Journal of Physical and Chemical Reference Data. 23 (1): 41–53. Bibcode:1994JPCRD..23...41D. doi:10.1063/1.555943. ISSN 0047-2689.
4. "Octane". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
5. "1988 OSHA PEL Project - Octane | NIOSH | CDC". www.cdc.gov. 2020-02-27. Retrieved 2024-04-19.
6. "Fractionation". www.appliedcontrol.com. Retrieved 2024-04-19.
7. Ross, Julian (January 1986). "Ullmann's Encyclopedia of industrial chemistry". Applied Catalysis. 27 (2): 403–404. doi:10.1016/s0166-9834(00)82943-7. ISSN 0166-9834.

External links

• International Chemical Safety Card 0933
• NIOSH Pocket Guide to Chemical Hazards. "#0470". National Institute for Occupational Safety and Health (NIOSH).
• Dr. Duke's Phytochemical and Ethnobotanical Databases, Octane,

• Alkanes
• Hydrocarbons