Stabilities of alkenes can be measured by comparing heats of hydrogenation.

Reaction: C=C + H2 → CH-CH

Ranking of alkene stability based on enthalpy of hydrogenation
Values (in kcal/mol) taken from the NIST Webbook and reflect more current values. To get values in kJ/mol, multiply by 4.19 J/cal.

Ethylene

Monosubstituted

Average ΔH°r:  -30
Ethylene

-32.4


 Propene
Propene
 -29.5


1-Butene
1-Butene
 -30.0


1-pentene
1-pentene
 -30.0


1-hexene
1-hexene
 -29.8


3-methyl-1-butene
3-methyl-1-butene
 -30.1


3,3-dimethyl-1-butene
3,3-dimethyl-1-butene
 -30.0

E-disubstituted

Average:  -27.4

Z-disubstituted

Average:  -28.2
E-2-butene
E-2-butene
 -27.4
 Z-2-butene
Z-2-butene
 -28.3
E-2-pentene
E-2-pentene
 -27,2
 Z-2-pentene
Z-2-pentene
 -28.1
E-2-hexene
E-2-hexene
 -27.7
 Z-2-hexene
Z-2-hexene
 -28.5
E-3-hexene
E-3-hexene
 -28.1
 Z-3-hexene
Z-3-hexene
 -29.0
E-4-methyl-2-pentene
E-4-methyl-2-butene
 -27.3
 Z-4-methyl-2-pentene
Z-4-methyl-2-butene
 -27.9


Cyclohexene
cyclohexene
 -28.3


Cyclopentene
cyclopentene
 -26.9


Cyclobutene
cyclobutene
 -31.5

1,1-Disubstituted

Average:  -27.9

Trisubstituted

Average:  -26.5
2-methylpropene
2-methylpropene
 -28.1
 2-methyl-2-butene
2-methyl-2-butene
 -26.6
2-methyl-1-butene
2-methyl-1-butene
 -28.2
 2-methyl-2-pentene
2-methyl-2-pentene
 -26.6
2-methyl-1-pentene
2-methyl-1-pentene
 -27.8
 E-3-methyl-2-pentene
E-3-methyl-2-pentene
 -26.3
2,3-dimethyl-1-butene
2,3-dimethyl-1-butene
 -27.8
 Z-3-methyl-2-pentene
Z-3-methyl-2-pentene
 -26.4
2-ethyl-1-butene
2-ethyl-1-butene
 -27.6
 1-methylcyclohexene
1-methylcyclohexene
 -26.6
Methylenecyclohexane
Methylenecyclohexane
 -28.5
 1-methylcyclopentene
1-methylcyclopentene
 -24.0
Methylenecyclopentane
Methylenecyclopentane
 -27.7

Tetrasubstituted


2,3-dimethyl-2-butene
2,3-dimethyl-2-butene

-26.3