Explain the role of latent heat in the change of state of a substance.

Explanation

i. The heat energy required to change substance from one state to another at constant temperature is called as latent heat of substance.
ii. When latent heat is supplied to a substance it is utilised for weakening the bonds between atoms or molecules of the substance.
iii. When solid substance is provided with latent heat of fusion, weakening of bonds results into distancing of atoms or molecules of solids and eventually it changes into liquid state.
iv. Similarly, when liquid substance is provided with latent heat of vaporisation, it changes into gaseous state. ltbr. v. Conversely when latent heat is released or given off from a substance, it results into strengthening the bonds between atoms or molecules causing change of state of the substance.
vi. When a liquid substance gives off latent heat of fusion, bonds between atoms or molecules grow stronger bringing them closer and eventually liquid changes into solid.
vii. Similarly, when a gaseous substance gives off latent heat of vaporisation, it changes into liquid.