Answer:
7916.59 J of heat is required
Step-by-step explanation:
the total heat required is
total heat = sensible heat to heat the liquid until boiling + heat to vaporise all the compound and take it to the gas state + heat required to heat the gas until the final temperature
Q = Q1+ Q2+ Q3
where
Q1 = m * cL * ΔTL
Q2 = m * Lv
Q3= m * cG * ΔTG
cL and cG are the specific heats of the liquid and gas respectively . ΔTL and ΔTG are the temperature changes for liquid and gas. Lv is the molar latent heat of vaporisation.
the mass based latent heat of vaporisation is
Lv m = Lv / M = 27.49 kJ/mol / 187.5 gr/mol =0.1466 kJ/g , where M= molecular weight of C2Cl3F3 ( calculated by summing all the molecular weights of its elements)
therefore
Q1 = m * cL * ΔTL = 38 g * 0.91 J/gK * ( 47.6°C - 12.3°C) = 1186.09 J
Q2 = m * Lv m= 38 g * 0.1466 kJ/g * 1000J/kJ = 5570.8 J
Q3 = m * cG * ΔTG = 38 g * 0.67 J/gK * (93.15°C - 47.6°C ) = 1159.70 J
thus
Q = Q1+Q2+Q3 = 1186.09 J + 5570.8 J + 1159.70 J = 7916.59 J