1.05 Kinetics

• What must particles do in order to react?


  Collide with sufficient energy (activation energy) and the correct orientation
• Do most collisions result in a reaction?

  No
• Define activation energy.


  The minimum energy that particles must collide with for a reaction to occur
• What does a Maxwell-Boltzman curve look like?

  
• What is the effect of increasing temperature on rate of reaction. Why?


  • Increasing temperature = increased rate of reaction
  • Much higher proportion of particles have energy greater than activation energy = many more successful collisions per second = increased rate
• What is the effect of increasing pressure/concentration on rate of reaction. Why?


  • Increased concentration/pressure = increased rate of reaction
  • There are more particles in a given volume = more frequent successful collisions = increased rate
• What is a catalyst?

  A substance which increases the rate of reaction but is not used up in the reaction
• How do catalysts work and how do they increase the rate of reaction?

  • Provides an alternative reaction pathway, with a lower activation energy
  • Lowers activation energy, so more particles have energy that is more than their activation energy, so more frequent successful collisons, so increased reaction rate