Chemical Forums
Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Win,odd Dhamnekar on July 04, 2021, 11:25:03 AM

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) :rarrow: SO_{2}(g) and CCl_{2}F_{2}(l) :rarrow: 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?

Answer is correct.