Answer with Explanation
The equations must be used to calculate the heat associated with phase change is,
Q=m×∆H(vap)
or Q=m×∆H(fus)
here;
∆H= heat required for one gram of the substance to undergo the phase change.
*If you're going from solid to liquid, you use ∆H-heat of fusion (called the heat of fusion), which represents the heat required for 1 gram of a substance to change from solid to liquid at the melting point.
*If you're going from liquid to gas, you use ∆H-heat of vaporization (called the heat of vaporization), which represents the heat required for 1 gram of the substance to change from liquid to gas at boiling point.
For water, the values are usually given to be
ΔHfus = 334 J/g and
ΔHvap=2257 J/g.