Stability of a crystal is reflected in the magnitude of its melting point, comment. Collect melting points of solid water, ethyl alcohol, diethyl ether and methane from data book. What can you say about the intermolecular forces between these molecules?
Higher the melting point, greater are the forces
holding the constituent particles together and hence greater is its stability.
The intermolecular forces in water and ethyl alcohol are mainly the hydrogen bonding but the intermolecular H-bonding in water is stronger than that in ethyl alcohol. Therefore, water has a higher melting point than ethyl alcohol.
Diethyl ether is a polar molecule. The intermolecular forces present in them are dipole-dipole attraction. Methane is a non-polar molecule. Therefore, the intermolecular forces operating in them are the weak van der Waals’ forces (London dispersion forces).