Chemistry 12

Name: ________________________

Kinetics Quiz /25 Part I: Multiple Choice Questions—circle the correct response. [13 marks] 1. Why does increasing temperature increase reaction rate? (A) decreases activation energy (B) decreases the percentage of effective collisions (C) increases activation energy (D) increases the percentage of effective collisions 2. Which represents the activation energy for the forward reaction in the diagram below?

(A) A (B) B (C) C (D) D 3. Which type of change is best for monitoring the reaction rate of the reaction below? Mg(OH)2(s) + 2 HCl(aq)  2 H2O(l) + MgCl2(aq) (A) colour (B) mass (C) pH (D) volume 4. Which describes an activated complex? (A) has a lower potential energy than products (B) has a lower potential energy than reactants (C) stable species that forms upon collision of reactants (D) unstable species that forms upon collision of reactants 5. Which term refers to a single step in a reaction mechanism? (A) elementary (B) fundamental (C) intermediate (D) primary 1

Chemistry 12

Name: ________________________

6. Why does hydrogen react quicker with Cl2 than with Br2? (A) Chlorine has a higher electronegativity than bromine (B) Chlorine is more acidic than bromine (C) Chlorine has a greater surface area than bromine (D) Chlorine is a gas whereas bromine is a liquid 7. Consider the following reaction: Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g) In two different experiments, equal moles of Zn and equal volumes of HCl are reacted. After 2 minutes, the volume of H2 produced is recorded as follows: Experiment 1 2

Zn(s) strip powdered

Temperature (0C) 10 15

HCl(aq) (mol/L) 10.0 3.0

Vol H2(g) (mL) 10.6 7.3

Which statement is TRUE? (A) (B) (C) (D)

Experiment 1 is faster due to the nature of the reactants. Experiment 1 is faster due to the concentration of HCl(aq). Experiment 2 is faster due to the powdered Zn(s). Experiment 2 is faster due to the temperature of the system.

8. For the reaction represented below, which is the rate determining step for the reverse reaction?

(A) A (B) B (C) C (D) D 9. How does a catalyst speed up a chemical reaction? (A) doubles the concentration of reactants (B) increases the frequency of collisions (C) lowers the heat of reaction (D) provides an alternate pathway

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Chemistry 12

Name: ________________________

10. Which represents the activation energy for the forward reaction? (A) A (B) B (C) C (D) D 11. What is H for the forward reaction? (A) -100 kJ (B) -40 kJ (C) 40 kJ (D) 100 kJ Refer to the mechanism below to answer the next two questions.

12. Which species is the catalyst? (A) H2O(l) (B) HOCl(aq) (C) HOI(aq) (D) OI-(aq) 13. Which is the rate determining step? (A) (B) (C) (D) 3

Chemistry 12

Name: ________________________

Part II: Extended Responses—Show ALL workings in space provided. [12 marks] 14. The activation energy for the equilibrium below is 85.0 KJ.

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[2] 15. (a) Explain the effect on reaction rate if the concentration of CO(g) is increased in the reaction below:

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Chemistry 12

Name: ________________________

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