5. Solution to Chemistry Problem

20. For pure benzene, the temperature dependences of the saturated vapor pressure are known at the liquid-vapor and crystal-vapor equilibrium
Crystals-vapor T,k 239.8 253.6 261.7 270.6 279.8
P, Pa 191 667 1333 2666 5330
Liquid-vapor T,k 279.8 285.7 294.1 303.0 315.4
P, Pa 5330 7999 6974 10404 16317 26660
Required:
1) Plot on MILLIMETER PAPER (Fig. 1) the temperature dependences of the saturated vapor pressure over a liquid substance and over a solid substance (crystals)
2) Plot on MILLIMETER PAPER ( Fig. 2) dependence of the natural logarithm of the saturated vapor pressure on the reciprocal temperature for the equilibria under consideration.
3) Determine the coordinates of the triple point.
4) Calculate graphically the molar heats of evaporation and sublimation, assuming that they do not depend on temperature.
5) Determine the molar enthalpy, entropy and Gibbs energy of melting at the triple point.