The Online Encyclopedia and Dictionary







Molecular formula C8H18
CAS number 111-65-9
EC number 203-892-1
Annex I Index number 601-009-00-8
Physical characteristics
Appearance Colourless liquid
Melting point -57 Celsius
Boiling point 126 Celsius
Vapour density -
Vapour pressure 11 mm Hg at 20 Celsius
Specific gravity 0.703
Flash point 15 Celsius (closed cup)
Explosion limits 0.96 - 6.5 %
Autoignition temperature 220 Celsius
Critical temperature 295.7 Celsius

Octane is an alkane hydrocarbon with the chemical formula CH3(CH2)6CH3. It has many isomers.

One of the isomers, the iso-octane 2,2,4-trimethylpentane , is of major importance, as it has been selected as the 100 point on the octane rating scale, with n-heptane as the zero point. Octane ratings are ratings used to represent the anti-knock performance of petrol, given as the percentage of 2,2,4-trimethylpentane in an 2,2,4-trimethylpentane / n-heptane mixture that would have the same performance. It is an important constituent of gasoline.

See also

External links

Last updated: 05-07-2005 14:11:57
Last updated: 05-13-2005 07:56:04