rates of reaction

• Measuring chemical reactions:

  Measure how fast the product is produced (normally the volume of gas produced)

  Measure how fast the reactant is used up (normally the weight of a reaction)
• rate graph:

  A) reaction stopped

  B) reaction here is fastest as graph is steepest

  
• rate graphs:

  A) faster reaction as it ends more quickly

  
• rate graphs

  A) higher volume of gas produced

  
• To increase the rate, the number of collisions in a reaction need to be increased.
• • Increase the temperature - this gives the particles more energy, when they are moving faster they are more likely to collide with each other
• • Increase the concentration - this increases the number of particles, the more particles the more collisions
• • Decreasing the particle size - this increases the surface area so therefore more ‘space’ for collisions
• A catalyst is a substance that can speed up the rate of a reaction without being used up itself.
• An example of a catalyst is iron in the Haber Process or platinum in a catalytic convertor.
• rates of reaction formula:

  A) average rate

  B) change in quantity

  C) change in time