Chapter 12 The Solid State - Study Questions - Page 467c: 35

18260 kJ

Heating the liquid: $\Delta H=12\ kg\times 4.7\ kJ/kg.K\times (-33.3--50)\ K=941.88\ kJ$ Boiling: $\Delta H=12\ kg\times23.33\ kJ/mol\div 17.03\ g/mol\times1000\ g/kg=16439\ kJ$ Heating the gas: $\Delta H=12\ kg\times 2.2\ kJ/kg.K\times (0--33.3)\ K=879.12\ kJ$ Total heat required: 18260 kJ