1. Rates of Reactions and Equilibrium Rates of Chemical Reactions The rate, or speed, of a chemical reaction is measured in units of a mass / time. Reaction rate = mass / time = g/min or g/sec

2. Rates of Reactions and Equilibrium Chemical Equilibrium Equilibrium Expression (K eq ) aA + bB  cC + dD K eq = [products] x / [reactants] y K eq = [C] c [D] d / [A] a [B] b Solids and liquids are not included in the K eq expression.

3. Rates of Reactions and Equilibrium Chemical Equilibrium Equilibrium Expression (K eq ) If Keq >1, then the products are favored. If Keq = 1, then neither products nor reactants are favored If Keq <1, then the reactants are favored. K eq = [products] x / [reactants] y

4. Rates of Reactions and Equilibrium Chemical Equilibrium Write the K eq for the for the reaction between sodium metal and water. 2Na (s) + 2H 2 O (l)  2NaOH (aq) + H 2(g) K eq =

5. Rates of Reactions and Equilibrium Le Chatelier’s Principle Once a chemical reaction has reached equilibrium, it will adjust to remain at equilibrium if it is stressed.

6. Rates of Reactions and Equilibrium Le Chatelier’s Principle Chemical equilibrium is like a balanced seesaw, if it is thrown off balanced by something, it will readjust to the balanced state.

7. Rates of Reactions and Equilibrium Le Chatelier’s Principle Stress Factors Change in concentration of a reactant or product. Change in the temperature of the system. Change in pressure on the system.

8. Rates of Reactions and Equilibrium Le Chatelier’s Principle 2Na (s) + 2H 2 O (l)  2NaOH (aq) + H 2(g) + heat If more water is added to this chemical reaction, will the equilibrium shift to the products side (right) or the reactant side (left)?

9. Rates of Reactions and Equilibrium Le Chatelier’s Principle 2Na (s) + 2H 2 O (l)  2NaOH (aq) + H 2(g) + heat If hydrogen gas is removed from this chemical reaction, will the equilibrium shift to the products side (right) or the reactant side (left)?

10. Rates of Reactions and Equilibrium Le Chatelier’s Principle 2Na (s) + 2H 2 O (l)  2NaOH (aq) + H 2(g) + heat If the temperature is increased on this chemical reaction, will the equilibrium shift to the products side (right) or the reactant side (left)?

11. Rates of Reactions and Equilibrium Le Chatelier’s Principle 2Na (s) + 2H 2 O (l)  2NaOH (aq) + H 2(g) + heat If pressure is increased on this chemical reaction, will the equilibrium shift to the products side (right) or the reactant side (left)?

12. Rates of Reactions and Equilibrium Le Chatelier’s Principle 2Na (s) + 2H 2 O (l)  2NaOH (aq) + H 2(g) + heat If this chemical reaction is cooled, will the equilibrium shift to the products side (right) or the reactant side (left)?