1. 6-3:Calculating Equilibrium Constants: The actual value of K eq is found experimentally. The individual concentrations of all the reactants is calculated, and the temperature recorded. This is because the value of K eq will change with temperature. What can K eq tell you? Which direction is favored.

2. Take the equiibrium: A(g) B(g) If the value of Keq is one then ….reaction is at equilibrium [A] = [B] If the value of Keq is less than one ……reactants are favored A(g)B(g) If the value of Keq is greater than one then ………products are favored A(g)B(g)

3. Calculating K eq for a reaction: 2SO 2 (g) + O 2 (g) 2SO 3(g) At equilibrium: [SO 2 ] = 1.50M [O 2 ] = 1.25M [SO 3 ] = 3.50M

4. At equilibrium: [SO 2 ] = 0.590M [O 2 ] = 0.045M [SO 3 ] = 0.260M Calculating K eq for a reaction: 2SO 2 (g) + O 2 (g) 2SO 3(g)

5. Calculate the equilibrium constant for the following reaction. 3H 2 (g) + N 2 (g) 2NH 3 (g) if at 25ºC there 0.15 mol of N 2, 0.25 mol of NH 3, and 0.10 mol of H 2 in a 2.0 L container.

6. Change moles to molarity: [N 2 ] = 0.15 mol/2.0L = 0.075 M [H 2 ] = 0.10 mol/2.0L = 0.050 M [NH 3 ] = 0.25 mol/2.0L = 0.125 M there 0.15 mol of N 2, 0.25 mol of NH 3, and 0.10 mol of H 2 in a 2.0 L container.

7. Calculate the equilibrium constant. Given N 2 (g) + 3H 2 (g) 2NH 3 (g) At 200ºC, the concentration of nitrogen is 2.12 M, the concentration of hydrogen is 1.75 M, and ammonia is 84.3 M, calculate the equilibrium constant.

9. Given PCl 5 (g) PCl 3 (g) + Cl 2 (g) Calculate the equilibrium constant of PCl 3 and Cl 2, if the equilibrium concentration for PCl 5 is 0.32 M and the equilibrium constant is 0.50.

10. The concentration of PCl 3 and Cl 2 is 0.40 M Cross multiply

11. Calculate the equilibrium concentration at 400ºC of NH 3, for the reaction: N 2 (g) + 3H 2 (g) 2NH 3 (g) The equilibrium concentrations for [N 2 ] = 0.45 and [H 2 ] = 1.10. The keq, at this temperature, is 1.7 x 10 -2.

12. Cross multiply

13. Questions p 559 Practice: # 1-4, Review: # 6-9 p 587 –Problems: # 24, 25,26,27 Answers: 7) 190; 8) 54.7; 9) 3.53x10 -3 M 24)a)0.67; b) 0.52; c) 310; 25) 1.4x10 10 26) 110.M; 27) 0.0250