1. Write the equilibrium constant expression for each of the following reactions:

a.  CH4 (g) + 2 H2S (g)--------> CS2(g) + 4H2(g)

b.  2NO(g) --------> N2(g) + O2(g)

c. 2 SO3(g) + CO2 (g) --------> CS2(g) + 4 O2(g)

2. What is the Kc for the following reaction at equilibrium if (N2O4)= 0.030M and (NO2)= 0.21M?

N2O4(g)----------> 2NO2 (g)

3. Indicate whether each of the following reactions contains mostly products, mostly reactants, or both reactants and products at equilibrium:

a. Cl2 (g) + 2NO (g) ---------> 2NOCl(g)     Kc= 3.7 * 10^8

b. H2O (g) + CH4 (g) --------> CO(g) + 3H2(g)   Kc= 4.7

c. 3O2 (g)------->  2O3 (g)   Kc= 1.7* 10^-56

4. In the lower atmosphere, oxygen is converted to ozone (O3) by the energy provided from lightning.

3O2 (g) + heat ------> 2O3 (g)

5. For each of the following changes at equilibrium, indicate whether the system shifts in the direction of the products, the reactants, or does not change:

a. add more O2 (g)

b. add more O3 (g)

c. increase the temperature

d. increase the volume of the container

e. add a catalyst