Answer
Please see the work below.
Work Step by Step
(a). We can define the molar heat of vaporization as the amount of heat required to vaporize one mole of a liquid.
(b). We can define the heat of fusion as the amount of heat required to melt one mole of a solid to liquid.
(c). We can define the molar heat of sublimation as the amount of heat that is required to sublime one mole of a solid into gas directly.
The units of the above mentioned terms are $\frac{J}{mol}or \frac{KJ}{mol}$.
