Concentration

• Collision theory


  Chemical reactions can only take place when the reacting particles collide with each other and the collisions must have sufficient energy
• Rate of a chemical reaction


  Determined by the frequency of successful collisions
• Large number of reactant molecules

  Rapid reactions initially
• Decreasing number of reactant molecules

  Reactions slow down over time
• All reactant molecules run out


  Reactions stop
• Containers with different concentrations

  • Same volume
  • Right container has twice the number of particles
• Increasing concentration of particles

  Increases the number of collisions per second
• Increasing concentration of particles

  Increases the rate of reaction
• Increasing concentration of particles in a gas

  Increases the gas pressure
• Higher concentration


  Faster reaction (steeper line)
• Higher concentration


  More product at the end