Unit 11--Reaction Rate Quiz

Multiple Choice (Choose the best answer.)

  1. The rate of a reaction depends upon:

    the concentration of the reactants.

    the temperature of the reaction.

    whether or not a catalyst is used.

    the nature of the reactants.

    All of the above are correct.

  2. Which of the following statment(s) about a reaction mechanism is/are true?

    I. The mechanism is the series of steps needed to complete a reaction.
    II. The rate of a reaction is only as fast as the slowest step in the mechanism.
    III. You can usually deduce the reaction mechanism from its reactants and products.

    I only

    II only

    III only

    I and II only

    I, II, and III

    Use your knowledge of collision theory and the energy distribution shown at right to answer questions 3 - 5. Assume that the graph shows the range of energies of collsion of a collection of reactants at two temperatures.

  3. Which is the highest temperature?

    T1 = T2

    T1 < T2

    T1 > T2

    It is impossible to tell.

  4. Which of the curves has the greatest number of collisions possessing the activation energy?

    T1 has the greatest number of collisions possessing the activation energy

    T2 has the greatest number of collisions possessing the activation energy

    Both have an equal number of collisions possessing the activation energy.

    It is impossible to tell.

  5. If a catalyst were used, how would the distributions change?

    Both curves would shift to the right.

    Both curves would shift to the left.

    The activation energy would shift to the right.

    The activation energy would shift to the left.

    Nothing about the distriibutions would change.

    Use your knowledge of collision theory and the potenial energy digram shown at right to answer questions 6 - 10. Assume the energy values are in Kilojoules.
  6. Which letter shows the potential energy of the activated complex?

    A

    B

    C

    D

    E

  7. What is the H of the reaction?

    + 35 KJ

    - 35 KJ

    + 25 KJ

    - 10 KJ

    None of these are correct.

  8. Which letter shows the activation energy?

    A

    B

    C

    D

    E

  9. How would the graph change if the temperature were raised?

    A and D would have higher energies.

    C would be greater.

    The activation energy would decrease.

    More than one of the above are correct.

    No change in the graph would occur.

  10. How would the graph change if a catalyst were used.

    A and D would have higher energies.

    C would be greater.

    The activation energy would decrease.

    More than one of the above are correct.

    No change in the graph would occur.

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