Rates reviews for test

Grade 12 – Rates of reaction review terms
  •  Important terms and concepts
  •  Rate
  •  Rate law
  •  Order of reaction
  •  Law of mass action
  •  Photochemical reactions
  •  Positive catalyst
  •  Negative catalyst
  •  Homogenous catalyst
  •  Heterogeneous catalyst
  •  Mechanism of reaction
  •  Elementary steps
  •  Units of the different order
  •  Rate constant k
  •  Difference between order and molecularity
  •  Pseudo unimolecular reactions
  •  Initial rate method
  •  Graphical method for determining order
  •  Integrated rate law method
  •  Collision theory
  •  Factors affecting rates of reaction
  •  Energy of activation
  •  Threshold energy
  •  Transition state
  •  Graphs for single step reactions
  •  Graphs for multi steps reaction
  •  Energy of activation for reverse reactions
  •  Orientation and its effect on rates of reaction
  •  Energy of activation and its effect on rates of reaction
  •  Calculation of Activation energy
  •  Calculation of order of reaction from initial rate method
  •  Calculation of rate constant from rate law
  •  Calculation of concentration for first order reactions after time ‘t’
  •  Calculation of rate constant or decay constant from half life
  •  Calculation of rate of reaction from concentration and time
  •  Explanation of Maxwell Boltzmann distribution curve
  •  Arrhenius equation
Problems –  You ought to be familiar with the following type of problems – that does not mean all these types of problems will be present in your test. Variations of these problems can be given either in the MCQ or Problems.
  • Determination of rate from concentration / volume / pressure etc and time
  • Determination of order by initial rate method – problems
  • Determination of rate constant ‘k’
  • Determination of average rate and instantaneous rate from a graph
  • Relation between rate and concentration change for determining order
  • Determination of concentration / time / rate constant from integrated rate law and half life
  • Arrhenius equation and determination of Ea or energy of activation
  • Determination of rate constant k / Ea / or effect of temperature on rate of reaction with change in temperature using modified Arrhenius equation
  • Determination of concentration of reactants after ‘n’ half lives
Format of test SCH4U / TOPS
  • Multiple Choice Questions =
  • Short Answers =
  • Problems =
  • Application level questions based on topics taught will be included.


  1. sir,

    the first question in the assignment the “rate determining step” asks for the best mechanism for the experiment, in part e).

    The overall equation is 2A + B –> 3C + D.

    The rate law equation is R = k [A]^2[B]

    Mechanism 1
    B –> Y (fast)
    Y + A –> D + Z (slow)
    Z + A –> 3C (fast)

    Mechanism 2
    A + B –> Y (fast)
    Y + A –> 3C + D (slow)

    The rate determining step for both mechanisms don’t match with the rate law equation. I don’t understand the reasoning that they have mentioned either. Can you please explain?

    1. A suggestion to your question has been given on Chemistry forums or precisely on this link

      There was an error in this link please excuse now it stands corrected

      Post your questions on the chemistry forums, if I am not able to solve there will be some one else who might be able to solve it for you