Why is using the Gibbs function advantageous when studying chemical and phase equilibrium? For Eq. 14.6 to apply at equilibrium, must a system attain equilibrium at fixed T and p? Show that (dA) T,V  ...

Why is using the Gibbs function advantageous when studying chemical and phase equilibrium?

For Eq. 14.6 to apply at equilibrium, must a system attain equilibrium at fixed T and p?

Show that (dA)_T,V  0 is a valid equilibrium criterion, where A = U ̶ TS is the Helmholtz function.

A mixture of 1 kmol of CO and kmol of O₂
is held at ambient temperature and pressure. After 100 hours only an insignificant amount of CO₂
has formed. Why?

Why might oxygen contained in an iron tank be treated as inert in a thermodynamic analysis even though iron oxidizes in the presence of oxygen?