Question: how much energy would be required to vaporize 45.0 grams of water?
Answer: The answer is 116 kJ . c - water's specific heat - 4.184 J/g⋅∘C . Then, you must provide enough heat to get all the water from liquid to steam. This is calculated using water's enthalpy of vaporization, ΔHvap - 40.68 kJ/mol .