1. Calculating Equilibrium Constants Using the ICE method to solve for K

2. Heterogeneous Equilibrium • REMEMBER! p.623 • Pure Solids or Pure Liquids are not included in equilibrium expressions because [Solids], [Liquids] are constant.

3. Calculating Equilibrium Constants • EASY when all concentrations are known! • JUST like on the quiz! EX. For the reaction: H2(g) + I2(g) ↔ 2 HI(g) At equilibrium, the concentrations are found to be: [H2] = 0.106 M [I2] = 0.035 M [HI] = 1.29 M K = ___[HI]2___ [H2][I2]K = ___(1.29 M)2 (0.106 M)(0.035 M)K = 4.49 x 102

4. What if you don’t know all equilibrium concentrations? • USE ICE METHOD! • ICE is a simple acronym for the titles of the first column of the table. • I stands for initial concentration. • C stands for the change in concentration. • E is for the concentration when the reaction is at equilibrium.

5. Grab your example! • Turn to pg. 626 Sample Exercise 15.9 • Watch This! Write Balanced Equation MAKE ICE BOX underneath Write K Expression 4. Assign Variables 5. Bring Down Stoichiometric Coefficients 6. Assign Charges (- R and + P) 7. Calculate Change(s) 8. PLUG E back into K Expression