Enter all MC answers into the Response System

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1 Kinetics Unit Test AP Chemistry Please Do Not Write On MC Exam Enter all MC answers into the Response System Base your answers to questions 1 and 2 on the possible rate laws below for the reaction: A + B C (A) Rate = k[b] 2 (B) Rate = k[b][a] (C) Rate = k[b] 2 [A] (D) Rate = k[b][a] 2 (E) Rate = k[b] 2 [A] 2 1. When [A] is tripled and [B] is constant then the initial rate of reaction remains constant. A) A B) B C) C D) D E) E 2. When the concentrations of [A] and [B] are tripled, the initial rate of reaction will increase by 27 times. A) A B) C C) D D) E E) C and D 3. A + 2 B 2 C + 4 D The rate law for the above reaction is A) [C] 2 [D] 4 B) k[c] 2 [D] 4 C) second order D) first order E) impossible to find without experimental data 4. BaCO3(s) + 2H + (aq) Ba 2+ (aq) + H2O(l) + CO2(g) + Heat Based on the above reaction, which will increase the rate of evolution of carbon dioxide? A) Adding water to the system B) Decreasing the temperature C) Finely powdering the BaCO3 D) Increasing the barium ion concentration, [Ba 2+ ] E) Decreasing the volume of the system Base your answers to questions 5 and 6 on on the table below, for the following reaction: 2 SO2 + O2 2 SO3 5. What is the experimental rate law for the reaction above? A) Rate = k[so2][o2] 3 B) Rate = k[so2] 3 [O2] 2 C) Rate = k[so2][o2] D) Rate = k[so2] 3 [O2] E) Rate = k[so2] 3 6. The value of the rate constant, k, for this reaction is A) B) C) D) E) Page 1

2 7. Which of the following is not correlated with a fast reaction rate? I. Catalysts II. High temperature III. High concentration of reactants IV. Strong bonds in the products V. Low level of activation energy A) I and II only B) I, II, and IV only C) III, IV, and V only D) IV and V only E) They are all correlated with a fast reaction rate 8. Increasing the temperature increases the reaction rate. This is best explained by a(n): A) new reaction path B) higher activation energy C) increased concentration of reactants D) increased number of effective collisions E) increased kinetic energy Base your answers to questions 9 and 10 on the graph below showing the energy during a catalyzed reaction. 9. Which is the curve for the lowest temperature? A) Curve T1 B) Curve T2 C) Curve T3 D) Can t tell 10. The temperature is changed from T3 to T2. Which area shows the number of additional molecules which can react? A) Area A B) Area C C) Area C + B D) Area A + B + C E) Area A + B 11. Which of the following would react most rapidly? A) powdered Zn in 1.0 M HCl at 25ºC B) powdered Zn in 2.0 M HCl at 25ºC C) a lump of Zn in 2.0 M HCl at 25ºC D) a lump of Zn in 1.0 M HCl at 40ºC E) a lump of Zn in 1.0 M HCl at 30ºC Page 2

3 Base your answers to questions 12 through 14 on the diagram shown below. 12. Which represents the energy of the activated complex? A) 6 B) 2 C) 3 D) 4 E) Which represents the activation energy for the forward reaction? A) 1 B) 2 C) 3 D) 4 E) A catalyst would change A) 1 and 6 B) 2 and 3 C) 3 and 4 D) 4, 5 and 6 E) 3 and N2O(g) 2 N2(g) + O2(g) The catalyzed reaction above occurs in three steps 1. Cl2(g) 2 Cl(g) 2. 2 N2O(g) + 2 Cl(g) 2 N2(g) + 2 ClO(g) 3. 2 ClO(g) Cl2(g) + O2(g) Which substance is the catalyst? A) Cl(g) B) Cl2(g) C) N2O(g) D) ClO(g) E) O2(g) Page 3

4 16. According to the above reaction mechanism, the distanced marked "Z" represents A) the activation energy for A(g) + B(g) «C(g) + D(g) B) the heat of reaction for for A(g) + B(g) «C(g) + D(g) C) the activation energy for C(g) + D(g) «A(g) + B(g) D) the heat of reaction for C(g) + D(g) «A(g) + B(g) E) none of these 17. Based on the potential energy diagram above, which of the following is true for this reaction? A) DH(kJ) = +20; Activation energy(kj) = 60; Reaction type: Endothermic B) DH(kJ) = +60; Activation energy(kj) = 60; Reaction type: Endothermic C) DH(kJ) = +40; Activation energy(kj) = 60; Reaction type: Exothermic D) DH(kJ) = 40; Activation energy(kj) = 60; Reaction type: Exothermic E) DH(kJ) = +40; Activation energy(kj) = 60; Reaction type: Endothermic 18. Step 1: Cu 2+ + Sn 2+ Cu(s) + Sn 4+ Step 2: Cu 2+ + Sn(s) Cu(s) + Sn 2+ Step 3: 2Be(s) + Sn 4+ Sn(s) + 2Be +2 In the above proposed reaction mechanism, what would be the products of the overall catalyzed reaction? A) Sn 2+ and Be +2 B) Sn 4+ and Sn 2+ C) Sn(s) and Sn 4+ D) Cu 2+ and Cu(s) E) Cu(s) and Be In a reaction mechanism, the rate determining state is the A) fastest and has the lowest activation energy B) fastest and has the highest activation energy C) slowest and has the lowest activation energy D) slowest and has the highest activation energy E) intermediate and has the lowest activation energy Page 4

5 20. Step 1: Cl(g) + O3(g) ClO(g) + O2(g) Step 2: O(g) + ClO(g) Cl(g) + O2(g) According to the above reaction mechanism, the reaction intermediate is A) Cl B) O2 C) O3 D) ClO E) O Page 5

6 Answer Key Kinetics Unit Test 1. A 2. E 3. E 4. C 5. D 6. A 7. E 8. D 9. C 10. E 11. B 12. A 13. D 14. D 15. B 16. C 17. E 18. E 19. D 20. D Page 6