Lime (CaO) is used to prevent SO2 from escaping smokestacks of coal burning power plants by the formation of solid CaSO4•2H2O also known as the mineral gypsum. One of the important reactions in the overall process is the dissociation of CaCO3(s).

Question

b. If a 12.0 g sample of solid CaCO3 is placed in an evacuated vessel at 725oC, what will the pressure of CO2 be when the system reaches equilibrium?

c. Which of the following actions cause an increase in the pressure of CO2 in the vessel described in question 2 above? Make your choice then justify your answer.
i. Addition of He gas
ii. Addition of SO3 gas
iii. Addition of more CaCO3 solid
iv. Increasing the volume of the vessel

d. If a 12.0 g sample of solid CaCO3 is placed in a vessel at 750oC in which the pressure of CO2 is 2.5 atm what mass of lime will form?

Answer 1

For a, do you have a Kc or Kp? Or does the question assume ALL of the CaCO3 decomposes?

Answer 2

I have part b if that helps
100 g of CacO3 give 44 g of CO2

so 12 g will give 5.28 g of CO2

so moles of CO2 = 0.12 moles

Volume = 0.12 X 22.4 L = 2.688 L

PV = nRT

Pressure = 0.12 X 0.0821 X 998 / 2.688 = 3.65 atm