Home work assignment "Phase diagrams and phase relations"

You are working out the phase relations in the three$-$component system $Cu-O-S$ considering these five phases: CuS,$C{u}_{2}S,$CuO,$C{u}_{2}O,$ and native $Cu.$

a$)$ How many univariant lines and how many invariant points do you expect to find in an $f{O}_2-f{S}_2$ diagram?

b$)$ Make a sketch of the principle topology of the phase relations in an $f{O}_2$ vs$.f{S}_2$ diagram.

a$)$ Construct a $T-x_{CO2}$ Diagram $(p=100$ bar$)$ for the decarbonation reaction of calcite using the data given below. Assume ideal behavior of $C{O}_2$ in the gas phase.

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