Equilibrium:

The following are sample non multiple choice questions taken from recent exams: 
These particular questions cover:

      • Equilibrium constant-
        Intrepretation, simple calculations.
      • Le Chatelier's Principle
      • The equilirium constant, standard free energy, and the reaction quotient.
      • K, DG0, and Q
Question 1 and 2 are concerned with the following equilibrium:

Carbon dioxide and hydrogen can react to form carbon monoxide and water. 
The equililibrium constant, Kc, for this reaction is 0.080 at 4000C.
CO2(g) + H2(g) ==  CO(g) + H2O(g)
1.If 1.0 M of carbon dioxide and 1.5 M of hydrogen are mixed together, calculate the approximate equilibrium concentration of carbon monoxide.
2.Is this approximation valid? SHOW YOUR WORK.