Question

Latent heat of vaporisation is used to
(a) overcome the forces of attraction between molecules in solid state.
(b) increase the kinetic energy of molecules in liquid state.

(c) overcome the forces of attraction between molecules in liquid state.
(d) increase the kinetic energy of molecules in vapour state.

Answer 1

Answer:

b

this is the ans

Explanation:

hope this may help

Answer 2

Answer:

Latent heat of vaporization is used to overcome the forces of attraction between molecules in liquid state.

Therefore, the option (c) is correct.

Explanation:

• According to kinetic theory, the total energy is the sum of the potential energy and the kinetic energy. During the phase transition the energy is supplied such as vaporization in which liquid changes into a gas. The phase transition occurs at constant temperature. Therefore, the kinetic energy will remain same.
• The energy required to increase the separation between the molecules so that, they overcome the force of attraction between the molecules is called Latent heat.

• In the liquid state molecules are closer to each other but less closer than in solids . So, they experience the force of attraction between the molecules. The energy used to overcome these attraction is latent heat of vaporization.
• So, when transition happens from liquid to vapor phase, a large amount of energy required to completely erase the force of attraction between the molecules.
• Therefore the latent heat of vaporization is large in the comparison of latent heat for other phase transitions.