Variable
benzene
2-methylpropane
isoprene
ethyne
ethane
n-butane
cis-2-butene
trans-2-butene
n-octane
propene
propane
n-heptane
2-methylpentane
2-2-4-trimethylpentane
n-pentane
toluene
n-hexane
ethene
2-methylbutane
1-butene
2-methylpropene
2-2-dimethylpropane
2-methylhexane