[UPSC CSE 2013] Thermodynamics (Q92, 15M)

The vapour pressure, in mm of Hg, of a substance in solid state is given by the relation \ln p=23.03-\dfrac{3754}{T}, where T is in Kelvin. The vapour pressure, in mm of Hg, of the substance in liquid state is given by the relation \ln p=19.49-\dfrac{3063}{T}. Calculate \begin{qroman}\item the coordinates of the triple point, and \item the latent heat of vaporisation at the triple point.\end{qroman} Take Gas constant R=8.314\ \mathrm{J\,mol^{-1}\,K^{-1}}.