Question

why ice contain more energy than water at same temperature of 273k​

Answer 1

This is because of the fact that phase transition occurs at same temperature. Hence, ice at 1bar pressure will melt to become liquid water at 273K. Thus the latent heat of fusion is used which comes to be around 335KJ/kg.

Answer 2

Because at 0° C (273 K) particles of water have more energy comparing it to water at the same temperature.