refer to: Physical Properties of Alkanes
Melting / Boiling Point
Alkenes are simple molecular substances with weak forces of attraction between molecules (weak intermolecular forces of attraction)
hence in general, alkenes have low melting and boiling points.
similar to alkanes:
- gradual increase in melting and boiling points of alkenes down the homologous series.
boiling points of ethene, propene, butene, very similar to those of alkanes with same number of carbon atoms.
Viscosity
Alkenes become more viscous as their molecular size increases. due to stronger forces of attraction between the alkene molecules.
Solubility
- Alkenes are insoluble in water
- Alkenes are soluble in most organic solvents like hexane and tetrachloromethane
unlike liquid alkanes → e.g. hexane, liquid alkenes are not used as solvents because they are more reactive and may interfere with reactions
Alkenes are more often used as starting materials in the manufacture of various products such as plastics and detergents.