1. Free Energy What is free energy?
How is enthalpy and entropy related to free energy?

2. Chem II:Gibbs Free Energy and Chemical Equilibrium
Infinite Campus Update:
Acid-Base Reactions Exam(28pts.)
Thermochemistry Exam(16pts.)
Objectives:
Review Gibbs Free Energy Equation
Review factors that influence speed of reactions.
Determine what chemical equilibrium is for reversible reactions.

3. Gibbs Free Energy Equation
Explain whether or not this reaction increases or decreases in entropy.
Explain whether or not this reaction increases or decrease in enthalpy
Explain whether or not this reaction is spontaneous or not.

4. Gibbs Free Energy Review

5. Chem II:Gibbs Free Energy and Chemical Equilibrium 3.24.16
Infinite Campus Update:
Third Quarter Grades posted.
Objectives:
Review Gibbs Free Energy Equation
Review factors that influence speed of reactions.
Determine what chemical equilibrium is for reversible reactions.

6. Chemical Reactions Rates
Reaction Rates = how fast the reactants chemically change into the products.
Collision Theory: Reactant particles will form products when reactants collide:
at the right position.
and exchange the right amount of kinetic energy.

7. Rates of Chemical Reactions
2.Explain what you would do with each factor below to increase the rate of a chemical reaction?
Temperature
Concentration of Reactants
Surface Area of Reactants
Catalysts
Inhibitors

8. Catalysts
Catalysts speed up reactions, but they are not apart of the chemical reaction.
Ex. Enzymes keep your body temperature around 37oC (98 oF) by speeding up important biological reactions.

9. Catalyst and Energy Change

10. Inhibitors Inhibitors slow down a chemical reaction.
Inhibitors bind to a catalyst and prevent it from speeding up a reaction.
Ex. Preservation of food. Antioxidants prevent foods from becoming stale or moldy.

11. Chemical Reaction Energy Diagram
Activation Energy:
The amount of energy needed to chemically convert reactants to products.

12. Rates of Chemical Reactions
What are factors that can affect speed of reactions?

13. Types of Chemical Reactions
1. Synthesis (R+ S ----> RS)
2. Decomposition (RS------> R+ S)
3. Single Replacement (T+ RS ---> TS + R)
4. Double Replacement (R+S- + T+U- ---> R+U-+ T+S-)
5. Combustion (CxHx + O > CO2 + H2O)
6. Neutralization (Acid + Base--> H2O + Salt)
(type of double replacement reaction)

14. Chem II:Gibbs Free Energy and Chemical Equilibrium 3.25.16
Objectives:
Review factors that influence speed of reactions.
Determine what chemical equilibrium is for reversible reactions.

15. Chem II:Gibbs Free Energy and Chemical Equilibrium 3.28.16
Objectives:
Determine what chemical equilibrium is for reversible reactions. (qualitatively/quantitatively)

16. Chemical Reaction Rate
1. Use the graph below to define what a chemical reaction rate is.

17. Chemical Reaction Rate
1. Use the graph below to define what a chemical reaction rate is.

18. Chemical Reactions
Why is it that most chemical reactions do not go to 100% completion?

19. Chemical Reactions
Why is it that most chemical reactions do not go to 100% completion?
Most reactions are reversible.
Reversible Reactions: The forward and reverse reactions for a system occurs simultaneously.
A double arrow is used in an equation that is reversible.

20. Reversible Reactions
What does this graph tell you about reversible reactions?

21. Chemical Reactions
Why is it that most chemical reactions do not go to 100% completion?
Most reactions are reversible.
Reversible Reactions: The forward and reverse reactions for a system occurs simultaneously.
A double arrow is used in an equation that is reversible.

22. Chemical Equilibrium
When the rates (speed) of the forward and reverse reactions are equal to one another.
Does it also mean the concentration of reactants and products are equal?

23. Chemical Equilibrium Equilibrium Position:
The concentration of reactants and products remain constant.
Indicates which direction is most favored. (forward)

24. Chemical Equilibrium

25. Chemical Equilibrium
N2 +3H NH3

26. Equilibrium Constants
Ratio of product to reactant concentrations at equilibrium, K(eq)
Concentration expressed in molarity.
aA + bB cC + dD
Equilibrium constant identifies which reaction is favored at equilibrium.
Keq > 1: favors forward or products
Keq <1: favors reverse or reactants
No units for equilibrium constant

27. Chem II:Gibbs Free Energy and Chemical Equilibrium 3.30.16
Objectives:
Determine what chemical equilibrium is for reversible reactions. (qualitatively/quantitatively)
Identify stresses that alter the chemical equilibrium position of a system. (Le Chatelier’s Principle).

28. Chemical Equilibrium

29. Chemical Equilibrium What factors can affect chemical equilibrium?
LeChatelier’s Principle:

30. Chemical Equilibrium What factors can affect chemical equilibrium?
-Concentration of substances in the reversible reaction.
-Temperature
-Pressure
LeChatelier’s Principle:
-If a stress is exerted on system in equilibrium, the system changes in a way to relieve that stress.
-The equilibrium position will change.

31. Chem II:
Objectives:
Review factors that influences the speed of a reaction.
Determine what chemical equilibrium is for reversible reactions. (qualitatively/quantitatively)
Identify stresses that alter the chemical equilibrium position of a system. (Le Chatelier’s Principle).
*Le Chatelier’s Principle Lab*
Homework:
Complete Chemical Equilibrium Packet-due tomorrow
Chemical Equilibrium/Le Chat Quiz-Wednesday

32. LeChatelier’s Principle Lab
Pre-Lab:
Predict how the system will respond to addition of specified substances.
Procedures:
Goggles must be worn at all times-No exceptions!
Post-Lab Questions:
Complete questions after lab or as homework.

33. Le Chatelier’s Principle Lab
Purpose:
Hypothesis:
Predict how the system will react to the stresses applied to test tubes #2-4.
What is the purpose of the control(test tube number one) in this experiment?

34. Chem II: 4.05.16 Due: Chemical Equilibrium Packet Le Chatelier’s Lab
Objectives:
Review factors that influences the speed of a reaction.
Determine what chemical equilibrium is for reversible reactions. (qualitatively/quantitatively)
Identify stresses that alter the chemical equilibrium position of a system. (Le Chatelier’s Principle).
Homework:
Chemical Equilibrium/Le Chat Quiz-Wednesday
Chemical Equilibrium Review-Kahootz 

35. Calculating Chemical Equilibrium
A liter of a gas mixture at equilibrium at 10oC contains mol of N2O4 and mol of NO2. N2O4 (g) 2NO2 (g) a.Write the expression for the equilibrium constant for the reaction above. b. Calculate the equilibrium constant for the reaction. c. Based on the Keq value, is the product or reactants favored in this reversible reaction? Explain.

36. Changes in Chemical Equilibrium
1. Using Le Chatelier’s Principle, explain how the equilibrium position of this reaction is affected by the following changes?
N2O4(g) + 58J > 2NO2(g)
Addition of heat:
b. Decrease in pressure :
c. Addition of NO2:
d. Removal of N2O4(g):

38. Chem II:
Objectives:
Chemical Equilibrium/Le Chat Quiz
Review factors that influences the speed of a reaction.
Determine what chemical equilibrium is for reversible reactions. (qualitatively/quantitatively)
Identify stresses that alter the chemical equilibrium position of a system. (Le Chatelier’s Principle).
Identify and apply K(sp) constant.

39. Solubility Equilibrium Constant
1. What does the solubility equilibrium constant represent, K(sp). 2. What is the K(sp) equation? 3. What factor(s) influence the K(sp) value?

40. Solubility Equilibrium Constant
1. What does the solubility equilibrium constant represent, K(sp). 2. What is the K(sp) equation? 3. What factor(s) influence the K(sp) value?

41. Solubility Equilibrium
Also called solubility equilibrium product, K(sp) : the product of the ions’ concentration values
K(sp) expression:
Dependent upon temperature
Determines the degree of solubility
for the compound.

42. Solubility Equilibrium
Also called solubility equilibrium product, K(sp) : the product of the ions’ concentration values
K(sp) expression:
Dependent upon temperature
Determines the degree of solubility
for the compound.

43. Chem II:
Infinite Campus:
Chemical Equilibrium/Le Chat Quiz
Objectives:
Review Chemical Equilibrium/Le Chat Quiz
Review factors that influences the speed of a reaction.
Determine what chemical equilibrium is for reversible reactions. (qualitatively/quantitatively)
Identify stresses that alter the chemical equilibrium position of a system. (Le Chatelier’s Principle).
Identify and apply K(sp) constant.

44. Solubility Equilibrium Constant, Ksp
Rank these solutions from least to most
Pb(SO4), Ksp: 6.3x10-7
Zn(OH), Ksp: 3.0x10-16
Ca(SO4), Ksp: 2.4x10-5
2.What is the concentration of lead ions and chromate ions in a saturated lead chromate,Pb(CrO4) solution at 25oC?
Ksp(PbCrO4) = 1.8x10-14
3. What is the concentration of magnesium ions and hydroxide ions in a saturated magnesium hydroxide solution, Mg(OH)2?
KspMg(OH)2 =7.1x10-12

45. Solubility Equilibrium Constant, Ksp
Rank these solutions from least to most
Pb(SO4), Ksp: 6.3x10-7
Zn(OH), Ksp: 3.0x10-16
Ca(SO4), Ksp: 2.4x10-5
2.What is the concentration of lead ions and chromate ions in a saturated lead chromate,Pb(CrO4) solution at 25oC?
Ksp(PbCrO4) = 1.8x10-14
3. What is the concentration of magnesium ions and hydroxide ions in a saturated magnesium hydroxide solution, Mg(OH)2?
KspMg(OH)2 =7.1x10-12

47. Chemical Equilibrium Calculations
R=ratio; I=[Initial]; C=[change]; E= [at equilibrium]

48. Chemical Equilibrium Calculations Worksheet #2
R=ratio; I=[Initial]; C=[change]; E= [at equilibrium]