The correct option is (c).
Explanation
Latent Heat of Vaporisation is the specific amount of heat energy required to change a unit mass of a liquid into a gas at its boiling point, without any change in temperature.
- Statement 1 is Incorrect: Latent Heat of Vaporisation refers to the heat energy absorbed when a liquid changes into a gas. The energy released when a gas turns back into a liquid is technically termed the Latent Heat of Condensation.
- Statement 2 is Correct: Steam at 100°C possesses higher internal energy than boiling water at the same temperature. This is because steam contains the additional latent heat absorbed during the phase transition from liquid to gas. This excess energy explains why steam burns are more severe than burns from boiling water.
- Statement 3 is Correct: During the process of vaporisation, the heat supplied is utilized to overcome the intermolecular forces of attraction holding the liquid particles together. Since this energy is used for phase change rather than increasing the kinetic energy of the particles, the temperature of the substance does not rise.
Key Takeaway: Latent heat represents the energy absorbed or released during a phase change at a constant temperature. In the case of water, steam carries significantly more energy than boiling water due to the absorption of the latent heat of vaporisation.