Calcium oxide, CaO, is manufactured by decomposition of calcium carbonate, CaCO3, in a furnace at 500 K:

CaCO3(s)?CaO(s)+CO2(g)

The spontaneity of a reaction can be determined from the free energy change for the reaction, ? G ?.

A reaction is spontaneous when the free energy change is less than zero.

A reaction is nonspontaneous when the free energy change is greater than zero.

A reaction is in equilibrium when the free energy change is equal to zero.

A:

For the decomposition of calcium carbonate, consider the following thermodynamic data:

? H ?rxn	178.5kJ/mol
? S ?rxn	161.0J/(mol?K)

Calculate the temperature in kelvins above which this reaction is spontaneous.

T = ?

B:

Calculate the equilibrium constant for the following reaction at room temperature, 25 ?C:

CaCO3(s)?CaO(s)+CO2(g)

K = ?