Question

The state of water changes from liquid to vapour on heating at ${100}^{\circ }C$. This process is known as

• A. Heat is absorbed.
• B. Heat is released.
• C. Temperature increases.
• D. Temperature decreases.

Answer 1

The correct option is B

Heat is released.

On application of heat, water in liquid form changes its state to gaseous. This occurs due to an increase in the kinetic energy of the water molecules. This process is known as boiling. This occurs at ${100}^{\circ }C$ where the temperature does not change and only the state of water changes.