Variable
benzene
pentenes
isoprene
cis-2-pentene
2-methylpropane
o-xylene
ethane
1-3-butadiene
cis-2-butene
trans-2-butene
n-hexane
n-butane
propane
n-heptane
propene
ethene
2-methylbutane
1-butene
2-methylpropene
m-p-xylene