Syllabus notes from unit 4 AQA kinetics. A2 level

HideShow resource information

Rate equation

Rate = k [A]x [B]Y

  • rate = mol dm-3 s-1 = change of conc per unit time
  • k = rate constant
  • A, B are reactants
  • [ ] = conc = mol dm-3
  • Overall order of reaction = X +Y
1 of 4

Deriving rate equation from experimental data


  • collecting gas evolved
  • colorimetry
  • titration

If reactant conc doubles and rate doubles = order 1

If reactant conc doubles and rate quadroubles = order 2

If rate independent to conc = order 0

2 of 4

changes of temp on K


  • different for every reaction
  • varies with temp
  • if all concentrations of all species in the rate equation are 1 mol dm-3, then the rate equation is equal to the value of k
  • units obtained by cancelling
  • for every 10k rise in temp reaction rate doubles
  • allows comparisons of speeds of different reactions at a given temp
  • larger the value of k, the faster the reaction
  • values of k increases with temp.
3 of 4

rate determining step

  • slowest step of reaction
  • controls overall rate
  • any step that occurs afterwards will not effect rate.
4 of 4


No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Rates resources »