Before the introduction of chlorofluorocarbons, sulfur dioxide (enthalpy of vaporization, 6.00 kcal/mol) was used in household refrigerators. What mass of SO

_{2} must be evaporated to remove as much heat as evaporation of 1.00 kg of CCl

_{2}F

_{2} (enthalpy of vaporization is 17.4 kJ/mol)? The vaporization reactions for SO

_{2} and CCl

_{2}F

_{2} are SO

_{2}(l)

SO

_{2}(g) and CCl

_{2}F

_{2}(l)

CCl

_{2}F

_{2}(g) respectively.

My answer: Molar mass of CCl

_{2}F

_{2}=120.9135 g

So, 1.00 kg of CCl

_{2}F

_{2}=[itex]\frac{1000g}{120.9135 g}=8.27[/itex] moles

ΔH°

_{vap} of CCl

_{2}F

_{2}=17.4 kJ/mol

So, for 8.27 moles of CCl

_{2}F

_{2}, total ΔH°

_{vap} is 17.4 kJ × 8.27 moles= 143.9 kJ

Molar mass of SO

_{2} =64.0638 g,

ΔH°

_{vap} of SO

_{2} is 25.1208 kJ/mol

[itex] \frac{143.9 kJ}{25.1208 kJ}[/itex]= 5.73 moles of SO

_{2}5.73 moles × 64.0638 g = 367 g of SO

_{2} must be evaporated.

Is this answer correct?