Statement A: Molar heat of vaporisation of water is greater than benzene.Statement B: Molar heat of vaporisation is the amount of heat required to vaporise one mole of liquid at constant temperature.

We know that heat of vaporisation of water at 100oC is 40.6 kJ and that of benzene is 31 kJ at 80oC. The amount of heat required to vaporise one mole of liquid at constant temperature is known as heat of vapourisation therefore, both assertion and reason are true but reason is not the correct explanation of assertion.