1. Equilibrium Practice

2. Types of Equilibrium Problems
Writing Equilibrium Expressions given Chemical Equation
Solving for K given Equilibrium Concentrations
Converting Kc and Kp
Manipulating Values of K (or Q)
Determining the Direction of Equilibrium Shift given Initial Concentrations and K
Solving for an Equilibrium Concentration given K and All Other Equilibrium Concentrations
Solving for K given Initial Concentrations and At Least One Equilibrium Concentration
Solving for Equilibrium Concentrations given Initial Concentrations and K

3. Writing Equilibrium Expressions given Chemical Equation

4. Write the equilibrium expressions for the following reactions:
N2(g) + 3H2(g) ⇋ 2NH3(g)
C3H8(g) + 5O2(g) ⇋ 3CO2(g) + 4H2O(g)
N2O4(g) + O3(g) ⇋ N2O5(s) + O2(g)

5. Solving for K given Equilibrium Concentrations

6. The following results were collected for two experiments at the same temperature. Show that the equilibrium constant is the same in both cases.
3SO2 + O2 ⇋ 2SO3
Experiment Experiment 2
Initial
Equilibrium
[SO2]0 = 2.00 M
[SO2] = 1.50 M
[O2]0 = 1.50 M
[O2] = 1.25 M
[SO3]0 = 3.00 M
[SO3] = 3.50 M
Initial
Equilibrium
[SO2]0 = M
[SO2] = M
[O2]0 = 0 M
[O2] = M
[SO3]0 = M
[SO3] = M

7. The reaction of the formation of nitrosyl chloride 2NO(g) + Cl2(g) ⇋ 2NOCl(g) The pressures at equilibrium were found to be: PNOCl = 1.2 atm PNO = 0.05 atm PCl2 = 0.30 atm Calculate the value of Kp for this reaction.

8. Converting Kc and Kp

9. From the previous problem, calculate K from Kp assuming the reaction was carried out at 25oC NO(g) + Cl2(g) ⇋ 2NOCl(g)

10. Manipulating Values of K (or Q)

11. Given K = 3.2 x 10-5 for H2(g) + O2(g) ⇋ 2H2O(g) Calculate the value of K for the following reactions:
6H2(g) + 3O2(g) ⇋ 6H2O(g)
2H2O(g) ⇋ 2H2(g) + O2(g)
H2O(g) ⇋ H2(g) + ½ O2(g)

12. Given:. C(s) + O2(g) ⇋ CO2(g). K = 3. 9 x 10-2. S(s) + O2(g) ⇋ SO2(g)
Given: C(s) + O2(g) ⇋ CO2(g) K = 3.9 x S(s) + O2(g) ⇋ SO2(g) K = 2.6 x C(s) + 2S(s) ⇋ CS2(l) K = 87.9 Calculate the value of K for: CS2(l) + 3O2(g) ⇋ CO2(g) + 2SO2(g)

13. Determining the Direction of Equilibrium Shift given Initial Concentrations and K

14. For the synthesis of ammonia at 500oC, the equilibrium constant is 0
For the synthesis of ammonia at 500oC, the equilibrium constant is Predict the direction in which the system will shift to reach equilibrium in each of the following cases.
Case 1
[NH3]0 = M
[N2]0 = 1.0 x 10-5 M
[H2]0 = 2.0 x 10-3 M
Case 2
[NH3]0 = 2.00 x 10-4 M
[N2]0 = 1.50 x 10-5 M
[H2]0 = 3.54 x 10-1 M
Case 3
[NH3]0 = 1.0 x 10-4 M
[N2]0 = 5.0 M
[H2]0 = 1.0 x 10-2 M

15. Solving for an Equilibrium Concentration given K and All Other Equilibrium Concentrations

16. Consider the following experiment:
Consider the following experiment: N2O4(g) ⇋ 2NO2(g) the reaction has a Kp = 0.133, and the pressure of N2O4 at equilibrium is 2.71 atm. What is the equilibrium pressure of NO2?

17. Solving for K given Initial Concentrations and At Least One Equilibrium Concentration

18. At a certain temperature, a 1. 00 L flask initially contained 2
At a certain temperature, a 1.00 L flask initially contained 2.98 mol PCl3 and mol PCl5. After the system had reached equilibrium, mol Cl2 was found in the flask. Calculate the equilibrium concentrations of all species and the value of K.
PCl5 ⇋ PCl3 + Cl2

19. Solving for Equilibrium Concentrations given Initial Concentrations and K

20. Carbon monoxide reacts with steam to produce carbon dioxide and hydrogen. At 700 K, the equilibrium constant is Calculate the equilibrium concentrations of all species if 1.00 mol of each component is mixed in a 1.00 L container.

21. Assume that the reaction for the formation of gaseous hydrogen fluoride from hydrogen and fluorine has an equilibrium constant of 115 at a certain temperature. In a particular experiment, 2.0 M of each component was added to a flask. Calculate the equilibrium concentrations of all species.