Final answer:
Yes, it takes more energy to vaporize 1 kg of saturated liquid water. The equation that can be obtained from the enthalpies hfg, hf, and hg is ΔH = hf + hfg + hg.
Step-by-step explanation:
Yes, it is true that it takes more energy to vaporize 1 kg of saturated liquid water. The process of vaporization requires the molecules of liquid water to overcome the intermolecular forces holding them together and transform into vapor. This requires an input of energy in the form of heat.
The equation that can be obtained from the enthalpies hfg, hf, and hg is:
ΔH = hf + hfg + hg