Answer 1

Latent heat of fusion of ice is 3.34 × 10⁵ J/kg. It means that 3.34 × 10⁵ J of heat is required to change 1 kg of ice at 0°C into water at the same temperature. It means that 1 kg of water at 0°C has 3.34 × 10⁵ J more energy than 1 kg of ice at the same temperature.

To put it simply, when water is cooled, as soon as the temperature reaches 0°C, the latent heat of fusion from water starts getting removed and it starts getting converted into ice. Water converts into ice when heat is removed, and thus, 1kg of water contains more heat than 1kg of ice at the same temperature.