Phase equilibria, Physical Chemistry

Aug 2019
At 25°C we have for rhombic sulfur: ΔfG°= 0; S° = 31.88 ± 0.17 J /K/ mol ; and for monoclinic sulfur: ΔfG°=63 J/mol; S°= 32.55 ± 0.25 J/K/mol. Assuming that the entropies do not vary with temperature, sketch the value of 'μ' versus T for the two forms of sulfur. From the data determine the equilibrium temperature for the transformation of rhombic sulfur to monoclinic sulfur. Compare this temperature with the experimental value, 95.4°C, noting the uncertainties in the values of S°.