Rate of reaction and collision theory

• Reactions can go all sorts of different rates

  1. one of the slowest is the rusting of iron
  2. A moderate speed reactions is a metal (light magnesium ) reacting with acid to produce a gentle stream of bubbles
  3. A really fast reaction is an explosion where is all over In a fraction of a second
• The rate of reactions depends on four things

  1. Temperature
  2. Concentration ( or pressure for gasses )
  3. Catalyst
  4. Surface area of solids (or size of solid pieces )
• The rate of reaction simply depends on how often and how hard the reacting particles collide with each other
• When the temperature Is increased the particles all move quicker if they’re moving quicker ,they’re going to collide more often (if cold less colliding ,hot more colliding )
• Concentration

  If a solution is made more concentrated if mean there are more particles of reactant knocking about between the water molecules which makes collisions between the important particles more likely in a gas increasing the pressure mean the particles are more squashed up together so there will be more frequent collisions
• Larger surface area

  If one of the reactants is a solid then breaking it up into smaller pieces will increase the total surface area this mean that the particles around it in the solutions will have more area to work on ,so there’ll be more frequent collisions