Physical properties of alkenes

Alkenes are non-polar or, at most, weakly polar compounds. They are insoluble in water but soluble in non-polar organic solvents such as benzene, ether and chloroform, and they are less dense than water. As shown in Table 15.3, an alkene's boiling point rises steadily as the number of carbon atoms increases (171 K for ethene up to 337 K for hex-1-ene), following the same surface-area logic already met for alkanes in section 15.1.4. Also mirroring the alkane pattern, a branched alkene has a lower boiling point than the corresponding straight-chain alkene of the same molecular formula. Finally, an alkene's boiling point sits very close to that of the alkane sharing the same carbon ske …