When 0.100 mol of CaCO3 (s) and 0.100 mol of CaO (s) are placed in an evacuated container with a volume of 10.0-L and heated to 385 K, PCO2 = 0.220 atm after equilibrium is established: CaCO3(s) ⇌ CaO (s) + CO 2 (g) An additional 0.300 atm of CO2 (g) is pumped in. What is the total mass (in grams) of CaCO3 after equilibrium is re-established?

1 answer

This problem seems too simple. If I've screwed up I'm sure another tutor will let me know.
CaCO3(s) ==> CaO(s) + CO2(g)

Kp = pCO2 = 0.22 atm.
So if we add 0.3 atm EXTRA, the reaction must shift to use up the extra 0.3.
Use PV = nRT and solve for n = number of moles CO2 and that will be the as moles CaCO3. Then add the extra moles toltghe 0.100 mol to start to find total CaCO3 after equilibrium is re-established.