1. Equilibrium Constant Chemistry Mrs. Coyle

2. Equilibrium Position http://www.chm.davidson.edu/ronutt/che115/K/Sol_1.gif

3. Equilibrium Expression Equilibrium Constant, K eq  The concentrations are at the equilibrium position.  The K eq is constant for a given temperature regardless of the initial concentrations.

4.  K eq > 1, products favored in equilibrium  K eq < 1, reactants favored in equilibrium  K eq is not expressed with units.

5. Rules for K eq of Heterogeneous Equilibrium (more than one phase)  Only gases and solutes concentrations appear in the equilibrium expressions.  Pure liquids and solids do not affect the K eq, because they do not change.

6. Practice  2 SO 2(g) + O 2(g) ⇄ 2 SO 3(g) K eq =  AgCl(s) ⇄ Ag + (aq) +Cl - (aq) K eq =

7. Ex. 1: Calculate the K eq, given equilibrium concentrations N 2 O 4 (g) ⇄ 2 NO 2(g) At equilibrium at 10°C, [N 2 O 4 ]= 0.0045 M and [NO 2 ] = 0.030M. Calculate the K eq. At equilibrium at 10°C, [N 2 O 4 ]= 0.0045 M and [NO 2 ] = 0.030M. Calculate the K eq.Answer: K eq = 0.20