Question

The heat of fusion for water is the amount of energy needed for water to

A. freeze.

B. boil.

C. melt.

D. evaporate.

Answer 1

@chmvijay

Answer 2

The standard enthalpy of fusion (symbol: ΔH,fus), also known as the heat of fusion or specific melting heat, is the change in enthalpy resulting from the addition or removal of thermal energy from 1 mole of a substance to change its state from a solid to a liquid (melting) or the reverse processes of freezing. It is also called the latent heat of fusion or the enthalpy change of fusion, and the temperature at which it occurs is called the melting point.

When thermal energy is withdrawn from a liquid or solid, the temperature falls. When heat is added the temperature rises. However, at the transition point between solid and liquid (the melting point), extra energy is required (the heat of fusion). For freezing, the molecules of a substance arrange in an ordered state. For them to maintain the order of a solid, extra heat must be withdrawn. In the other direction, to create the disorder from the solid crystal to liquid, heat must be added.
Source:
wikipedia