Find what heat in calories (cal) is required to change 60 g of 100∘C boiling water into steam. The heat of vaporization for water Lv is 540 cal/g.

Question

Heat of vaporization : Q=mLv

Answer 1

To vaporize the water which is already at 100ºC, the only heat needed is that for the phase change. Thus, you have ...

60 g x 540 cal/g = 32,400 calories