Question
A sample of CaCO3 (s) is introduced into a sealedcontainer of volume 0.672 L and heated to 1000 K until equilibriumis reached. The Kp for the reaction, CaCO3(s) <--> CaO (s) + CO2 (g) is 3.7x 10-2 at this temperature. 1) Calculate the mass, in grams, of CaO(s) that is present @ equilibrium. A sample of CaCO3 (s) is introduced into a sealedcontainer of volume 0.672 L and heated to 1000 K until equilibriumis reached. The Kp for the reaction, CaCO3(s) <--> CaO (s) + CO2 (g) is 3.7x 10-2 at this temperature. 1) Calculate the mass, in grams, of CaO(s) that is present @ equilibrium.
Explanation / Answer
CaCO3(s) CaO (s) + CO2 (g) Since CO2 is the only gaseous component of the reaction, Kp = P (CO2) Hence at equilibrium, P(CO2) = 3.7 * 10^-2 atm T=1000 K V = 0.672 L Moles of CO2, n = P V / RT = 3.7 *10^-2 atm * 0.672 L / (0.0821 L-atm/mol.K * 1000 K) =3.03 * 10^-4 moles . As moles of CaO and CO2 formed are equal, moles of CaO = 3.03 *10^-4 moles . mass of CaO = moles * molar mass = 3.03 * 10^-4 moles * 56.08g/mol = 0.017 g . Hope this helps