Variable
benzene
pentenes
isoprene
o-xylene
ethyne
n-butane
2-methylpropane
ethylbenzene
propane
n-heptane
2-methylpentane
n-pentane
toluene
n-hexane
butenes
propene
ethene
2-methylbutane
ethane
m-p-xylene
2-methylhexane