Answer:
CH4 < CH3CH3 < CH3CH2CH3
Step-by-step explanation:
Alkanes are saturated aliphatic hydrocarbons that undergoes intermolecular Van der waals forces. Van der waals forces are the attractive forces which make it possible for non-polar molecules to form liquids and solids.
Van der waals force are described as intermolecular forces arising from induced fluctuating dipoles in atoms and molecules brought about by movement of electrons around the atomic nucleus.
An example of the Van der waals force is the london dispersion force that occurs in the alkane family. It is the weakest of all electrical forces that act between atoms and molecules, These forces are responsible for liquefaction or solidification of non-polar substances at low temperature.
The strength of the intermolecular forces is based on the number of electrons surrounding the molecule and the surface area of the molecule. SO, in alkanes, the longer the carbon chain, the more stronger the intermolecular forces.