Question

water stored in a earthen vessel becomes cool

Answer 1

because there are very tiny pores in the earthen vessel and the water keep moving to it and it evaporates taking the heat from the rest of the water which keeps the water cool

Answer 2

Answer:

During summer, water kept in an earthen pot becomes cool because of the phenomenon of evaporation. Earthen pot has a large number of tiny pores in its walls and some of the water molecules continuously keep seeping through these pores to outside the pot. This water evaporates continuously and take the latent heat required for vaporization from the remaining water. In this way, the remaining water loses heat and gets cooled