is it true that it take more energy to vaporize 1 kg of water?

Question

is it true that it take more energy to vaporize 1 kg of water saturated liquid at 100°C than it would at 120°C?

Answer 1

It takes ZERO energy to vaporize at 120C because its 100% vapor already. at STP

At 100C one has a Liquid + vapor stage that is possible, so its kind of an intermediate state in which water and vapor could exist together, so to fully vaporize one would need additional energy. So in Thermodynamics, its specified in problems that at 100C its either a FULL vapor, or a partial Vapor + water. Check your steam tables and see that this statement is indeed true.

So yes, it does take more at 100C for specific conditions where water + vapor exists. .

Answer 2

it is the very severe Latent warmth, approximately 540 cal/gram this is released whilst steam condenses. evaluate that to one million cal/g for each degree that water at a hundred stages loses whilst it touches your epidermis.