Definition of isooctane in US English:

isooctane

noun

Chemistry
  • A liquid hydrocarbon present in petroleum. It serves as a standard in the system of octane numbers.

    Chemical formula: (CH₃)₃CCH₂CH(CH₃)CH₃

    • ‘They are rated based on their ability to resist knocking against a standard mixture of two hydrocarbons, isooctane and heptane.’
    • ‘The end result is the addition of isobutane to isobutylene to form isooctane, the molecule that is the basis of octane ratings seen at the gas pumps.’
    • ‘The isooctane used was of spectroscopic grade.’
    • ‘Mix gasoline with the right number of hydrocarbons and you get isooctane.’

Pronunciation

isooctane

/ˌīsōˈäktān/