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
2F
2 (enthalpy of vaporization is 17.4 kJ/mol)? The vaporization reactions for SO
2 and CCl
2F
2 are SO
2(l)
SO
2(g) and CCl
2F
2(l)
CCl
2F
2(g) respectively.
My answer: Molar mass of CCl
2F
2=120.9135 g
So, 1.00 kg of CCl
2F
2=[itex]\frac{1000g}{120.9135 g}=8.27[/itex] moles
ΔH°
vap of CCl
2F
2=17.4 kJ/mol
So, for 8.27 moles of CCl
2F
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
25.73 moles × 64.0638 g = 367 g of SO
2 must be evaporated.
Is this answer correct?