Chapter 16 - Thermodynamics: Directionality of Chemical Reactions - Questions for Review and Thought - General Questions - Page 737f: 92b

38.17 kJ

$\Delta_{r}S^{\circ}=113\,J/K$ Boiling point: $T_{b}=(64.6+273.15)\,K=337.8\,K$ $\Delta_{r}S^{\circ}_{vap}=\frac{\Delta H_{vap}}{T_{b}}\implies\Delta H_{vap}=\Delta_{r}S^{\circ}_{vap}\times T_{b}$ $=113.0\,J/K\times337.8\,K=38.17\,kJ$