Energy Needed to Heat and Vaporize Water?
Calculate the energy needed, in kJ, to heat 36 grams of water from 50 ° C to 100 °C and then to completely vaporize it to steam at 100 °C. The specific heat of water is 4.18J/(K · g) and its enthalpy change of vaporization is 40.7 kJ/mol.
- Roger the MoleLv 72 years agoFavorite Answer
(4.18J/(K · g)) x (36 g) x (100 - 50) K = 7524 J = 7.524 kJ to heat the water to its boiling point
(36 g H2O) / (18.01532 g H2O/mol) x (40.7 kJ/mol) = 81.33 kJ to vaporize the water
7.524 kJ + 81.33 kJ = 89 kJ total