At 1 atm, how much energy is required to heat 47.0 g H2O (s) at -24.0 degrees celsius to H2O (g) at 121 degrees Celcius. How much energy is needed to heat 47.0 g H2O (l) from 0.0 to 100 degrees celcius? The specific heat of H2O (l) is 4.184 J(g * k )