Octane is an alkane hydrocarbon with the chemical formula CH₃(CH_Two)_{Half a dozen}CH_Three. It has several isomers.

One of a isomers, iso-octane or even 2,2,4-Trimethylpentane, is of major importance, when it has been selected as a C point on the octane rating scale, with n-heptane as the zero. Octane number come ratings utilized to represent a anti-knock performance of petroleum-based fuels (Octane is less in all likelihood to prematurely combust under pressure than heptane), given when a percentage of 2,2,4-trimethylpentane inorth an 2,2,4-trimethylpentane / n-heptane mixture that would keep close at hand a equivalent performance. These are an significant constituent of gasoline. Octane has Eighteen isomers :

 Octane
 Two-Methylpentane
 Three-Methylheptane
 Four-Methylheptane
 Three-Ethylhexane
 2,2-Dimethylhexane
 2,3-Dimethylhexane
 2,4-Dimethylhexane
 2,5-Dimethylhexane
 3,3-Dimethylhexane
 3,4-Dimethylhexane
 Two-Methyl, Three-Ethylpentane
 Three-Methyl, Three-Ethylpentane
 2,2,3-Trimethylpentane
 2,2,4-Trimethylpentane
 2,3,3-Trimethylpentane
 2,3,4-Trimethylpentane
 2,2,3,3-Tetramethylbutane