QuestionThermodynamics / Trouton-type relation
The entropy of vaporization of a liquid is 100 J mol⁻¹K⁻¹ and it boils at 300K. What would be the value of ∆Hvap?
- (a) 3.0 kJ mol⁻¹
- (b) 30.0 kJ mol⁻¹
- (c) 300 kJ mol⁻¹
- (d) 3000 kJ mol⁻¹
Answer: (b) 30.0 kJ mol⁻¹
At boiling point, ΔSvap = ΔHvap/Tb → ΔHvap = 100 × 300 = 30,000 J mol⁻¹ = 30.0 kJ mol⁻¹ → (b).