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Published byWendy Taylor Modified over 8 years ago
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Kinetics Lesson 3 Collision Theory
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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.
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Collision Theory Most collisions are not successful Collisions provide the energy required to break bonds. You need a collision to have a reaction.
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Collision Theory products no products 1.Favourable Geometry A successful collision requires: Poor Geometry
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2.Sufficient Energy to break the chemical bonds Activation energy is the minimum amount of energy required for a successful collision.
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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
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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:
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2.Increasing the reactant concentration increases the rate because there are: More frequent collisions
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The Collision Theory can be used to explain how the rate of a reaction can be changed. The catalyst KI is added to H 2 O 2, food colouring, and dishwashing detergent. The O 2 produced makes foam. Lowers the activation energy or Ea- allowing low energy collisions to be successful 3.Adding a catalyst Movie
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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
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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:
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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 H 2 and O 2 do not react at room temperature.
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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
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Explain each Scenario Using the Collision Theory 3.H 2 O 2 decomposes very slowly at room temperature. 2H 2 O 2(aq) → O 2(g) + 2H 2 O (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.
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Describe and Graph the Relationship between the Following Ea and the rate Ea Rate Decreasing the Ea increases the rate- inverse.
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Describe and Graph the Relationship between the Following Temperature and the rate Temp Rate Increasing the temperature increases the rate- direct.
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Describe and Graph the Relationship between the Following Concentration and the rate Conc Rate Increasing the concentration increases the rate- direct.
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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!
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Which factors increase the percentage of successful collisions? I.Increasing temperature II.Increasing concentration III.Increasing surface area IV.Adding a catalyst
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