Heterogeneous Chemical Equilibrium with Calcium Carbonate
Heterogeneous Chemical Equilibrium with Calcium Carbonate
Solid calcium carbonate () decomposes into solid calcium oxide () and gaseous carbon dioxide () in a constant-volume container at high temperatures. The equilibrium constant depends on temperature, which you can vary, and is equal to the pressure (in bars) divided by the standard-state pressure of 1 bar. Carbon dioxide is assumed to behave like an ideal gas, and the two solids are assumed to be in separate phases.
CaCO
3
CaO
CO
2
K
eq
CO
2
You can vary the number of moles of , , and added to the constant-volume container; the bar graph on the right shows the number of moles present at equilibrium. Note that adding (or when CaO (or ) is already in the container at equilibrium does not change equilibrium because the fugacity of the solid does not change. The container on the left represents the system; the color of the gas phase increases in intensity as the number of moles of increases.
CaCO
3
CaO
CO
2
CaO
CaCO
3
CaCO
3
CO
2