It is helpful in understanding graphs of thermodynamic functions to interpret them in terms of molecular behavior. Consider the plot of the temperature dependence of the standard molar Gibbs free energy of the three phases of a substance in Fig. 4J.3.

(a) Explain in terms of molecular behavior why the Gibbs free energy of each phase decreases with temperature.

(b) Explain in terms of molecular behavior why the Gibbs free energy of the vapor phase decreases more rapidly with temperature than that of the solid or liquid phase.

Fig. 4J.3

Transcribed Image Text:

E LLI Molar Gibbs free energy, G Liquid Solid Solid stable Vapor Liquid Vapor stable stable Temperature, T