A pressure cooker holds water and its vapour at an absolute pressure of

PHYSICS · Subjective · Fermi University Physics · Thermal, Statistical & Complex Systems · Interacting systems, real gases and phase equilibria · Interacting systems, real gases and phase equilibria

Thermal Physics, Ch Phase coexistence and the Clausius-Clapeyron relation

Problem

A pressure cooker holds water and its vapour at an absolute pressure of 177 kPa177\,\mathrm{kPa}. Water boils at 373.15 K373.15\,\mathrm{K} under 101.3 kPa101.3\,\mathrm{kPa}, and its molar latent heat of vaporisation is L=40.7 kJ mol−1L = 40.7\,\mathrm{kJ\,mol^{-1}}, taken as constant over the range in question. Treat the vapour as an ideal gas and neglect the molar volume of the liquid beside that of the vapour, so that the integrated vapour-pressure curve ln⁡p=const−L/RT\ln p = \text{const} - L/RT may be used, with R=8.314 J mol−1 K−1R = 8.314\,\mathrm{J\,mol^{-1}\,K^{-1}}. At what temperature does the water boil inside the cooker?

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