Explain why there is no rise temperature of water when it starts boiling although it is still being heated?

There is no rise in temperature of water when it starts boiling, even though it is still being heated. This is because the heat which is supplied helps in the increase of kinetic energy. That is, the heat is used to break the forces of attraction between water molecules and convert it into a gaseous state (Steam). This is called latent heat of vaporisation.

Explanation: -

When we supply heat to water, with the increase in temperature, the kinetic energy of particles in water also increases. The particles start moving faster. At a certain temperature, a point is reached when the energy supplied by heat overcomes the intermolecular force of attraction between the particles, and the particles move randomly at a greater speed in any direction. At this stage, the water starts boiling and gets converted into steam. Though we continue supplying heat, the temperature doesn’t rise and the thermometer reading remains constant. Because the heat supplied to water gets used up as latent heat to convert water into steam.