rate equations and orders

• zero order

  changes in concentration has no effect on rate

  e.g if A doubles the rate does not change
• first order

  changes in concentration has a proportional change on rate

  e.g. if A doubles then the rate doubles
• second order

  changes in concentration has a squared proportional change on rate

  e.g. if A doubles the rate quadruples
• how to work out orders (for this we are working out order for A)

  compare the experiments but finding where the concentration of A is changing but not the concentration of B

  compare the rate of the 2 experiments and the concentrations
• half life in zero order

  half life decreases

  (the time taken for half the substance to decompose decreases)
• half life of first order

  half life is constant

  (the time taken for half of the substance to decompose stays the same)
• half life of second order

  half life increases

  (the time taken for a substance to decompose increases)