Q. Explain the Heating curve for water?

Ans.

When a substance is heated, it undergoes several phase changes. A heating curve is a diagram which illustrates the phase changes that occur when a substance is heated. Let us look at the phase changes that occur when water is heated by examining its heating curve:

Note that the melting and boiling processes require the addition of a specific amount of energy to break the forces holding the water molecules together. When a liquid solidifies or condenses, the opposite occurs: energy is released.

The amount of heat required for melting is known as the heat of fusion. For example, the heat of fusion of water is 80 cal/g.

Similarly, the amount of heat required for boiling is known as the heat of vaporization. The heat of vaporization for water is 540 cal/g.