For an unknown liquid, 6.5 kJ of energy must be removed from 300.0 g of the compound in the vapor phase at its boiling point. What is the heat of vaporization of the unknown compound in Joules per gram?
q = mass H2O x delta Hvap
6,500 J = 300.0 g x delta Hvap.
Solve for delta Hvap in J/gram