Physical Properties
Boiling and melting points of alkenes are very similar to those of the corresponding alkanes. The E / Z stereochemistry affects the constants, especially the melting points, because of a better (E) or worse (Z) crystalline packing.
| Compound | Formula | b.p. (°C) | m.p. (°C) |
|---|---|---|---|
| Ethane | CH3CH3 | −89 | −183 |
| Ethene | CH2=CH2 | −104 | −169 |
| Propane | CH3CH2CH3 | −42 | −188 |
| Propene | CH2=CHCH3 | −48 | −185 |
| Butane | CH3(CH2)2CH3 | −1 | −138 |
| 1-Butene | CH2=CHCH2CH3 | −6 | −185 |
| cis-2-Butene | cis-CH3CH=CHCH3 | 4 | −139 |
| trans-2-Butene | trans-CH3CH=CHCH3 | 1 | −105 |