The amount of energy to boil water depends on two things: the amount of water and the temperature of the water when you start. The more water water, the more energy it takes. The colder the water,...
The minimum voltage necessary to generate hydrogen and oxygen from water by electrolysis is 1.23 V. It depends on how you do it if it will take that much or more (if you don't use the correct...
Assuming atmospheric pressure, ice of 0oC and steam of 100oC?
This equals the heat of fusion + the specific heat of water * 100 + the heat of vaporization
At 1 bar (rougly 1 atm):
heat of...