3.collisiontheory.ppt
- 2. The Collision Theory Link to Simulation of Molecular Motion 1. Matter is moving particles. 2. Temperature increases- particles move faster -more collisions -more collision energy. 3. Chemical reactions -bonds break -new bonds form 4. Collisions provide the energy.
- 3. Collision Theory Most collisions are not successful Collisions provide the energy required to break bonds. You need a collision to have a reaction.
- 4. Collision Theory products no products 1. Favourable Geometry A successful collision requires: Poor Geometry
- 5. 2. Sufficient Energy to break the chemical bonds Activation energy is the minimum amount of energy required for a successful collision.
- 6. The Collision Theory can be used to explain how the rate of a reaction can be changed. And that’s it! 3. Lower activation energy or Ea- low energy collisions are more effective. 2. Harder collisions- greater collision energy 1. More collisions Reaction rates can increase due to
- 7. The Collision Theory can be used to explain how the rate of a reaction can be changed. Harder collisions More collisions 1. Increasing the temperature increases the rate because there are:
- 8. 2. Increasing the reactant concentration increases the rate because there are: More frequent collisions
- 9. The Collision Theory can be used to explain how the rate of a reaction can be changed. The catalyst KI is added to H2O2, food colouring, and dishwashing detergent. The O2 produced makes foam. Lowers the activation energy or Ea- allowing low energy collisions to be successful 3. Adding a catalyst Movie
- 10. The Collision Theory can be used to explain how the rate of a reaction can be changed. Lower activation energy or Ea- allowing low energy collisions to be successful 4. Changing the nature of the reactant for a more reactive chemical increases the rate
- 11. The Collision Theory can be used to explain how the rate of a reaction can be changed. More frequent collisions 5. Increasing the surface area of a solid reactant increases the rate because:
- 12. Explain each Scenario Using the Collision Theory The spark provides the Ea and it explodes because it is exothermic A small spark ignites causes an explosion. Ea is too high for the room temperature collisions 1. A balloon full of H2 and O2 do not react at room temperature.
- 13. Explain each Scenario Using the Collision Theory It burns because it is exothermic The candle continues to burn The match provides the Ea A match causes the candle to burn Ea is too high for the room temperature collisions 2. A candle does not burn at room temperature
- 14. Explain each Scenario Using the Collision Theory 3. H2O2 decomposes very slowly at room temperature. 2H2O2(aq) → O2(g) + 2H2O(l) KI increases the reaction rate dramatically. Lowers the Ea- allows low energy collisions to be successful KI is a catalyst as it is not a reactant and it speeds up the rate.
- 15. Describe and Graph the Relationship between the Following Ea and the rate Ea Rate Decreasing the Ea increases the rate- inverse.
- 16. Describe and Graph the Relationship between the Following Temperature and the rate Temp Rate Increasing the temperature increases the rate- direct.
- 17. Describe and Graph the Relationship between the Following Concentration and the rate Conc Rate Increasing the concentration increases the rate- direct.
- 18. Describe and Graph the Relationship between the Following Ea and the temperature Ea Temp No relationship! The only way to change the Ea is by adding a catalyst!
- 19. Which factors increase the percentage of successful collisions? I. Increasing temperature II. Increasing concentration III. Increasing surface area IV. Adding a catalyst