[AL CHEM] Dynamic Equilibrium

Question

The equilibrium constant (in terms of partial pressures of gases) of the following reaction is 10atm at 1000k.

C(graphite) + CO2(g) <-----> 2CO(g)

What is the total pressure of an equilibrium system of CO(g), CO2(g) and the graphite containing 6% of CO2 by volume？

Answer 1

Denote the total pressure at equilibrium of the system as P.

Partial pressures at equilibrium :
pgraphite = 0 (because graphite is solid)
pCO2 = 0.06P
pCO = P - 0.06P = 0.94P

C(s) + CO2(g) = 2CO(g)
Kp = (pCO)2 / (pCO2) = 10 atm
(0.94P)2 / (0.06P) = 10 atm
Total pressure P = 0.679 atm