collision theory

• Collision theory


  A reaction requires 2 things to be successful: 1) a collision, 2) enough energy to overcome Activation Energy (Ea)
• Most collisions do not result in a reaction
• To increase the rate of reaction

  1. Increase temperature

  2. Increase the partial pressure (of gases)

  3. Increase the concentration (of solutions)

  4. Increase the surface area (of solids)

  5. Add a catalyst
• Temperature


  At a higher temperature, the average kinetic energy increases, therefore there are more collisions per second and the average collision energy is higher, resulting in more successful collisions per second and a faster reaction
• Pressure (gases only)


  Increasing the number of particles in the same volume means there would be more collisions per second, resulting in more successful collisions per second and a faster reaction
• Concentration (solutions only)


  Similar argument as for pressure
• Surface area (solids only)

  Increasing the surface area increases the number of available reaction sites, resulting in more successful collisions per second and a faster reaction