Water in its ice form has a usually high melting point temperature, a value close to 0°C. As a result of the interconnected lattice structure of water molecules in its solid form due to hydrogen bonding between molecules, a high input of energy is required to transform ice into its liquid form. This energy requirement is called the heat of fusion. Water has a heat of fusion value of 333.55 kJ/kg.
Heat of fusion of Water: is the amount of heat energy required to convert units of solid into liquid form without changing in temperature. For example, converting 1 gram of solid ice at 0oC required 334 Joules of heat.
Likewise, water in its liquid form has an unusually high boiling point temperature, a value close to 100°C. As a result of the network of hydrogen bonding present between water molecules, a high input of energy is required to transform liquid water into water vapor, an energy requirement called the heat of vaporization. Water has a heat of vaporization value of 40.65 kJ/mol