Variable
benzene
isoprene
ethyne
ethane
ethylbenzene
n-butane
propane
n-heptane
2-2-4-trimethylpentane
cyclo-hexane
toluene
n-hexane
propene
ethene
2-methylbutane
1-butene
2-methylpropene
2-2-dimethylpropane
2-methylhexane
m-p-xylene