Question

For the equilibrium:

CO(g) + H2O(g) ⇌ CO2(g) + H2(g) KC = 10.0

If 1.6 mol of CO and 1.6 mol of water are initially added to a 2.0 liter flask and the flask is then heated until the system comes to equilibrium, the concentration of hydrogen will then be _______ M.

Answer 1

Initial (CO) = initial (H2O) = 1.6 mol/2.0 L = 0.80 mols/L = 0.80 M
......................CO(g) + H2O(g) ⇌ CO2(g) + H2(g) KC = 10.0
I......................0.8...........0.8...........0...............0
C.......................-x............-x............+x.............x
E..................0.8-x.........0.8-x.............x.............x
Kc =10 = (CO2)(H2)/(CO)(H2O)
Substitute the E line into the Kc expression above and solve for x
Post your work if you get stuck. You can avoid a quadratic if you let 0.8-x = 0.8 but that MAY not be appropriate in this case. Check it out.