3. On scaled axes, construct a phase stability plot of the type of log as, vs log ao, for the Me-S-Osystem at 400 K using the thermodynamic information given below.

Assume that all solid phases are strictly stoichiometric. Clearly map out the stability fields for each phase and give the balanced reaction equations and associated mass action relationships for each equilibrium you identify for the diagram. Make certain critical numerical values are marked.

Fig: 1

Fig: 2