1. Lecture 41/25/06 Quiz Friday Seminar 1:30 on Friday

2. What if 1.00 mol of SO 2 and 1.00 mol of O 2 put into 1.00-L flask at 1000 K. At equilibrium, 0.925 mol of SO 3 have been formed. Calculate K Calculate K from concentrations

3. Skills - recap Need to be able to: Balance a reaction Equilibrium constant expression Make ICE table

4. Manipulating K Multiply the equation by a constant Reverse equation Add equations

5. Multiply by a constant 2SO 2 (g) + O 2 (g) ⇄ 2SO 3 (g) K = 283 vs. SO 2 (g) + ½ O 2 (g) ⇄ SO 3 (g) K = ?

6. Reversing the equation 2SO 2 (g) + O 2 (g) ⇄ 2SO 3 (g) K = 283 vs. 2SO 3 (g) ⇄ 2SO 2 (g) + O 2 (g) K = ?

7. Adding equations N 2 (g) + O 2 (g) ⇄ 2NO (g) K 1 = 4.3 x 10 -25 2NO (g) + O 2 (g) ⇄ 2NO 2 (g) K 2 = 6.4 x 10 9 N 2 (g) + 2O 2 (g) ⇄ 2NO 2 (g) K net = ?

8. Le Chatelier’s Principle system at equilibrium Disturb equilibrium Shifts system to new equilibrium Ways to disturb equilibrium

9. Add / Remove  Product /Reactant

10. Example: For the reaction, PCl 3 (g) + Cl 2 (g) ⇄ PCl 5 (g), the system is at equilibrium when [PCl 3 ] = 0.20 M, [Cl 2 ] = 0.125, [PCl 5 ] = 0.6 M. What is the new equilibrium, if the concentrations of Cl 2 is increased by 0.075 M?