No heat is supplied to a liquid during evaporation. How does then the liquid change into its vapours?
Though no heat is supplied to the liquid molecules near the surface of the liquid acquire sufficient kinetic energy by collisions with other liquid molecules and with this K.E. they overcome the attractive forces of other molecules and change into vapours.
During evaporation, particles of water absorb heat from the surroundings to change their state. The particles at the surface absorb more heat and change into vapour.