it is observed that the specific latent heat of vapour is greater than the specific latent heat of fusion?

Question

use kinetic theory to explain this effect

Answer 1

To fuse a solid to a liquid, all you have to do is get the atoms/molecules "moving." In vaporizing a liquid, you have to separate the atoms/molecules into individual, independent particles. In the first, you overcome the mutual attraction in a crystal. In the second, you absolutely have to overcome all mutual attraction and separate the particles.