1. Lecture 21/19/07 The Department of Natural Sciences Presents: “Problems and Progress in Recovery from Spinal Cord Injury: Neuroimmunology and Cell Biology " Michele Lemons, Ph.D. University of Utah Monday, Jan. 22, 2007 4:00 pm Fuller Auditorium Room 006 Testa Science Center Refreshments will be served

2. Equilibrium vs. Kinetics Equilibrium vs. Real world Catalysts

3. Consider the chemical reaction: A + B ⇆ C  You mix 1 mole of A with 1 mole of B.  At Equilibrium, the amount of C will be: 1.Between 0 and 1 moles 2.Exactly 1 mole 3.Between 1 and 2 moles 4.Exactly 2 moles

4. Equilibrium Constant (K) Direction of reaction does not matter Dependent on temperature not concentrations Leave out solids and water from the K expression

5. Example 1.H 2 (g) + I 2 (g) ⇄ 2HI (g) 2.S (s) + O 2 (g) ⇄ SO 2 (g) 3.NH 3 (aq) + H 2 O (l) ⇄ NH 4 + (aq) + OH - (aq)

6. Conversion of K c to K p aA +bB ⇄ cC + dD

7. Examples: Relate K c to K p 2NO 2 (g) ⇄ 2NO (g) + O 2 (g) N 2 (g) + O 2 (g) ⇄ 2NO (g)

8. Uses for Equilibrium constant (1) Does the reaction favor the products or reactants? K>>1 K<<1

9. (1) Does the reaction favor the products or reactants?

10. Compare Q (Reaction quotient) vs. K Q < K Q > K Q = K Uses for Equilibrium constant (2) Predict the direction of the reaction from initial concentrations