Choose the correct one --

When water boils , its temperature :

• increases
• decreases
• remain constant

Also give reason for the chosen answer.

The correct answer is remains constant.

When water is boiled, its temperature does not change until it has completely changed into the vapour state. This is because the heat which is supplied is used in changing the state by overcoming the forces of attraction between the water molecules. Thus, the heat is absorbed without showing any rise in temperature and is known as latent heat.