Question

On the cooling curve what happened to the temperature when the ice was freezing?explain

Answer 1

Look at the region on the curve where the chage of state is taking place. What do you notice?
(ice was freezing? Do you mean water was freezing, or ice was melting perhaps?)

Also, look over what you might have already studied having to do with the latent heat of fusion.

Answer 2

during changes of state: freezing or thawing, evaporating or condensing, the temperature remains constant during the process