Question

Why does temperature not change when ice melts to form water?

Answer 1

Immediately after the molecular bonds in the ice are broken the molecules aremoving (vibrating) at the same average speed as before, so their average kinetic energy remains the same, and, thus, their Kelvin temperature remains the same. Below is a picture of solidice melting into liquid water.

Answer 2

The temperature do not change when ice melt to form water because in 0° Celsius ice changed into water and water change into ice.