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Question
You are given normal boiling points and standard enthalpies of vapourisation. Calculate the entropy of vapourisation of liquids listed below.
| Liquid | Boiling points (°C) | ΔH (kJ mol−1) |
| Toluene | 110.6 | + 35.2 |
Solution
Given, Tb = 110.6°C = (110.6 + 273) = 383.6 K
ΔHV(toluene) = + 35.2 kJ mol−1
∆SV = `(Δ"H"_"V")/"T"_"b"`
∆SV = `(+ 35.2 "kJ mol"^-1)/(383.6 "K")`
∆SV = `(+ 35200 "J mol"^-1)/(383.6 "K")`
∆SV = + 91.76 J K−1 mol−1
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