1. Kinetics
Lesson 3
Collision Theory

2. The Collision Theory
Link to Simulation of Molecular Motion
1. Matter consists of moving particles.
2. As the temperature increases the particles move faster and collide more often and with more energy.
3. In chemical reactions bonds must be broken and new ones formed.
4. The energy for this comes from particle collisions.
5. The collisions have a variety of energy, as some are harder than others.
6. A collision energy diagram is a graph of the number of the collisions versus the energy of each collision.

3. Collision Energy Diagram Simulation
100 %
Percent of
Collisions
With
Energy
0 %
Low Collision energy High

4. Collision Energy Diagram
100 %
Percent of
Collisions
With
Energy
0 %
Activation Energy Ea- minimum energy required for a successful collision- to break the bonds!
Low Collision energy High

5. Collision Energy Diagram
100 %
Percent of
Collisions
With
Energy
0 %
Activation Energy Ea- minimum energy required for a successful collision- too break the bonds!
Low Collision energy High

6. Collision Energy Diagram
100 %
Percent of
Collisions
With
Energy
0 %
Activation Energy Ea- minimum energy required for a successful collision- too break the bonds!
This area represents the
fraction of collisions
that do not have the Ea-
not successful.
Low Collision energy High

7. Collision Energy Diagram
100 %
Percent of
Collisions
With
Energy
0 %
Activation Energy Ea- minimum energy required for a successful collision- too break the bonds!
This area represents the
fraction of collisions
with the Ea -successful.
Low Collision energy High

8. What happens to the number of successful collisions if we add a catalyst, which lowers the activation energy Ea?
Watch!

9. Collision Energy Diagram
100 %
Percent of
Collisions
With
Energy
0 %
Activation Energy Ea- minimum energy required for a successful collision- too break the bonds!
This area represents the
fraction of collisions
with the Ea -successful.
Low Collision energy High

10. Collision Energy Diagram
100 %
Percent of
Collisions
With
Energy
0 %
Activation Energy Ea- minimum energy required for a successful collision- too break the bonds!
Lowering the Ea increases successful collisions!
Low Collision energy High

11. What happens to the number of successful collisions if we increase the temperature- so that the average collision energy is greater?
Watch!

12. Collision Energy Diagram
100 %
Percent of
Collisions
With
Energy
0 %
Activation Energy Ea- minimum energy required for a successful collision- too break the bonds!
Low Collision energy High

13. Collision Energy Diagram
100 %
Percent of
Collisions
With
Energy
0 %
Activation Energy Ea- minimum energy required for a successful collision- too break the bonds!
Push the graph down and right!
Increasing the temperature increases successful collisions- increases rate!
Low Collision energy High

14. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:

15. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:

16. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1. Favourable Geometry

17. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1. Favourable Geometry
products

18. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1. Favourable Geometry versus Poor Geometry
products

19. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1. Favourable Geometry versus Poor Geometry
products

20. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1. Favourable Geometry versus Poor Geometry
products

21. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1. Favourable Geometry versus Poor Geometry
products

22. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1. Favourable Geometry versus Poor Geometry
products
no products

23. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1. Favourable Geometry versus Poor Geometry
products
no products

24. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
2. Sufficient Energy to break the chemical bonds

25. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
2. Sufficient Energy to break the chemical bonds

26. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
2. Sufficient Energy to break the chemical bonds

27. Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
2. Sufficient Energy to break the chemical bonds
Activation energy is the minimum amount of energy required for a successful collision.

28. The Collision Theory can be used to explain how the rate of a reaction can be changed.
Reaction rates can increase due to
1. More collisions
2. Harder collisions- greater collision energy
3. Lower activation energy or Ea, which allows low energy collisions to be more effective.
And that’s it!

29. The Collision Theory can be used to explain how the rate of a reaction can be changed.
1. Increasing the temperature increases the rate because there are:

30. The Collision Theory can be used to explain how the rate of a reaction can be changed.
1. Increasing the temperature increases the rate because there are:
More frequent collisions

31. The Collision Theory can be used to explain how the rate of a reaction can be changed.
1. Increasing the temperature increases the rate because there are:
More frequent collisions
Harder collisions

32. The Collision Theory can be used to explain how the rate of a reaction can be changed.
2. Increasing the reactant concentration increases the rate because there are:

33. The Collision Theory can be used to explain how the rate of a reaction can be changed.
2. Increasing the reactant concentration increases the rate because there are:
More frequent collisions

34. The Collision Theory can be used to explain how the rate of a reaction can be changed.
3. Adding a catalyst increases the rate because:

35. The Collision Theory can be used to explain how the rate of a reaction can be changed.
3. Adding a catalyst increases the rate because  
Lower activation energy or Ea, which allows low energy collisions to be successful
Movie- The catalyst KI is added to H2O2, food colouring, and dishwashing detergent. The O2 produced makes foam.

36. The Collision Theory can be used to explain how the rate of a reaction can be changed.
4. Changing the nature of the reactant for a more reactive chemical changes the rate because

37. The Collision Theory can be used to explain how the rate of a reaction can be changed.
4. Changing the nature of the reactant for a more reactive chemical changes the rate because
Lower activation energy or Ea, which allows low energy collisions to be more effective

38. The Collision Theory can be used to explain how the rate of a reaction can be changed.
5. Increasing the surface area of a solid reactant increases the rate because:

39. The Collision Theory can be used to explain how the rate of a reaction can be changed.
5. Increasing the surface area of a solid reactant increases the rate because:
More frequent collisions

40. Explain each Scenario Using the Collision Theory
1. A balloon full of H2 and O2 do not react at room temperature.
A small spark ignites causes an explosion.

41. Explain each Scenario Using the Collision Theory
1. A balloon full of H2 and O2 do not react at room temperature.
Ea is too high for the room temperature collisions
A small spark ignites causes an explosion.

42. Explain each Scenario Using the Collision Theory
1. A balloon full of H2 and O2 do not react at room temperature.
Ea is too high for the room temperature collisions
A small spark ignites causes an explosion.
The spark provides the Ea and it explodes because it is exothermic

43. Explain each Scenario Using the Collision Theory
2. A candle does not burn at room temperature
A match causes the candle to burn.
The candle continues to burn

44. Explain each Scenario Using the Collision Theory
2. A candle does not burn at room temperature
  Ea is too high for the room temperature collisions
A match causes the candle to burn.
The candle continues to burn

45. Explain each Scenario Using the Collision Theory
2. A candle does not burn at room temperature
  Ea is too high for the room temperature collisions
A match causes the candle to burn.
  The match provides the Ea
The candle continues to burn

46. Explain each Scenario Using the Collision Theory
2. A candle does not burn at room temperature
  Ea is too high for the room temperature collisions
A match causes the candle to burn.
  The match provides the Ea
The candle continues to burn
It burns because it is exothermic

47. Explain each Scenario Using the Collision Theory
3. H2O2 decomposes very slowly at room temperature.
2H2O2(aq) → O2(g) H2O(l)
KI increases the reaction rate dramatically.

48. Explain each Scenario Using the Collision Theory
3. H2O2 decomposes very slowly at room temperature.
2H2O2(aq) → O2(g) H2O(l)
KI increases the reaction rate dramatically.

49. Explain each Scenario Using the Collision Theory
3. H2O2 decomposes very slowly at room temperature.
2H2O2(aq) → O2(g) H2O(l)
KI increases the reaction rate dramatically.
KI is a catalyst as it is not a reactant and it speeds up the rate.

50. Explain each Scenario Using the Collision Theory
3. H2O2 decomposes very slowly at room temperature.
2H2O2(aq) → O2(g) H2O(l)
KI increases the reaction rate dramatically.
KI is a catalyst as it is not a reactant and it speeds up the rate.
Lowers the activation energy or Ea, which allows low energy collisions to be more effective

51. Describe and Graph the Relationship between the Following
 Ea and the rate
Rate Ea

52. Describe and Graph the Relationship between the Following
 Ea and the rate
Decreasing the Ea increases the rate- inverse.
Rate Ea

53. Describe and Graph the Relationship between the Following
 Ea and the rate
Decreasing the Ea increases the rate- inverse. Ea
Rate

54. Describe and Graph the Relationship between the Following
Temperature and the rate
Rate
Temp

55. Describe and Graph the Relationship between the Following
Temperature and the rate
Increasing the temperature increases the rate- direct.
Rate
Temp

56. Describe and Graph the Relationship between the Following
Temperature and the rate
Increasing the temperature increases the rate- direct.
Rate
Temp

57. Describe and Graph the Relationship between the Following
Concentration and the rate
Rate
Conc

58. Describe and Graph the Relationship between the Following
Concentration and the rate
Increasing the concentration increases the rate- direct.
Rate
Conc

59. Describe and Graph the Relationship between the Following
Concentration and the rate
Increasing the concentration increases the rate- direct.
Rate
Conc

60. Describe and Graph the Relationship between the Following
Ea and the temperature
Temp Ea

61. Describe and Graph the Relationship between the Following
Ea and the temperature
The only way to change the Ea is by adding a catalyst!
No relationship!
Temp Ea

62. Describe and Graph the Relationship between the Following
Ea and the temperature
The only way to change the Ea is by adding a catalyst!
No relationship!
Temp Ea