Test1 ch15 Kinetics Practice Problems, Lecture notes of Chemical Kinetics

Download Test1 ch15 Kinetics Practice Problems and more Lecture notes Chemical Kinetics in PDF only on Docsity! 1 General Chemistry II Jasperse Kinetics. Extra Practice Problems General Types/Groups of problems: Rates of Change in Chemical Reactions p1 First Order Rate Law Calculations P9 The look of concentration/time graphs p2 Reaction Energy Diagrams, Activation Energy, Transition States… P10 Rates: Average Rates, Determination of Rates from Stoichiometry and Changes of Other Chemicals p3 Reaction Mechanisms, Intermediates… P12 Reactant Order and Overall Reaction Order P4 Mechanism Steps and Rate Laws P13 Given a Rate Law, How much will rate change with change in concentration P5 Catalysts P14 Determining Reactant Orders from Actual Data P6 Answers P15 Actual Rate Law from Concentration/Rate Data P7 Determining Rate Constant from Actual Data. Where you yourself need to first deduce the rate law, then plug in the values to solve for “k”. P8 Rates of Change in Chemical Reactions 1. For the reaction A + 3B à 2C, how does the rate of disappearance of B compare to the rate of production of C? a. the rate of disappearance of B is 1/2 the rate of appearance of C b. the rate of disappearance of B is 3/2 the rate of appearance of C c. the rate of disappearance of B is 2/3 the rate of appearance of C d. the rate of disappearance of B is 1/3 the rate of appearance of C 2. For the reaction 2A + 3B → 4C + 5D, the rate of the reaction in terms of ΔA would be written as: a. –ΔA/Δt. d. +1/2 ΔA/Δt. b. –1/2 ΔA/Δt. e. –2 ΔA/Δt. c. +ΔA/Δt. 3. For the reaction 2A + 3B → 4C + 5D, the rate of the reaction in terms of ΔB would be written as a. –ΔB/Δt d. +1/3 ΔB/Δt b. +ΔB/Δt e. –3 ΔB/Δt c. –1/3 ΔB/Δt 4. For the reaction 2A + 3B → 4C + 5D, the rate of the reaction in terms of ΔC would be written as a. +ΔC/Δt d. d. –4 ΔC/Δt b. +4 ΔC/Δt e. –1/4 ΔC/Δt c. +1/4 ΔC/Δt 5. In the combustion of methane, CH4(g) + 2 O2(g) → CO2(g) + 2 H2O (g), which reactant has the greatest rate of disappearance? a. CH4 b. O2 c. CO2 d. H2O e. CH4 and O2 have the same rate of disappearance. 2 The look of concentration/time graphs 6. Which of the following is not a possible graph of concentration versus time for a reactant? a. c. b. d. 7. Assuming that each of the following graphs has the same concentration and time axes, which has the greatest initial rate of disappearance of reactant? a. c. b. d. 8. The following graph shows the kinetics curves for the reaction of oxygen with hydrogen to form water: O2(g) + 2H2(g) → 2H2O(g). Which curve is hydrogen? a. the dashed curve b. the gray curve c. the black curve d. either the gray or the black curve e. Any of these curves could be hydrogen 5 Given a Rate Law, How much will rate change with change in concentration 20. The reaction CHCl3(g) + Cl2(g) → CCl4(g) + HCl(g) has the following rate law: Rate = k[CHCl3][Cl2]. If the concentration of CHCl3 is increased by a factor of five while the concentration of Cl2 is kept the same, the rate will a. double. d. increase by a factor of five. b. triple. e. decrease by a factor of one-fifth. c. stay the same. 21. The reaction 2NO(g) + O2(g) → 2NO2(g) has the following rate law: Rate = k[O2][NO]2. If the concentration of NO is reduced by a factor of two, the rate will __________ a. double. d. be reduced by one-half. b. quadruple. e. remain the same. c. be reduced by one-quarter. 22. The rate of a reaction is found to double when the concentration of one reactant is quadrupled. The order of the reaction with respect to this reactant is __________ a. first. d. one-half. b. second. e. third. c. one-quarter. 6 Determining Reactant Orders from Actual Data 23. Given the following data, determine the order of the reaction with respect to Cl2. 2NO(g) + Cl2(g) → 2NOCl(g) Experiment [NO] (M) [Cl2] (M) Rate (M/s) 1 0.0300 0.0100 3.4 × 10–4 2 0.0150 0.0100 8.5 × 10–5 3 0.0150 0.0400 3.4 × 10–4 a. first d. fourth b. second e. fifth c. third 24. Given the following data, determine the order of the reaction with respect to H2. H2(g) + 2ICl(g) → I2(g) + 2HCl(g) Experiment [H2] (torr) [ICl] (torr) Rate (M/s) 1 250 325 1.34 2 250 81 0.331 3 50 325 0.266 a. one-half d. third b. second e. three-halves c. first 25. Given the following data, determine the order of the reaction with respect to NO(g). 2NO(g) + Cl2(g) → 2NOCl(g) Experiment [NO] (M) [Cl2] (M) Rate (M/s) 1 0.0300 0.0100 3.4 × 10–4 2 0.0150 0.0100 8.5 × 10–5 3 0.0150 0.0400 3.4 × 10–4 a. first d. fourth b. second e. fifth c. third 26. Determine the overall order of the reaction: H2(g) + 2ICl(g) → I2(g) + 2HCl(g) from the following data: Experiment PH (torr) PICl (torr) Rate (torr/s) 1 250 325 1.34 2 250 81 0.331 3 50 325 0.266 a. first d. fourth b. second e. zeroth c. third 27. Determine the overall order of the reaction 2NO(g) + Cl2(g) → 2NOCl(g) from the following data: Experiment [NO] (M) [Cl2] (M) Rate (M/s) 1 0.0300 0.0100 3.4 × 10–4 2 0.0150 0.0100 8.5 × 10–5 3 0.0150 0.0400 3.4 × 10–4 a. first d. fourth b. second e. fifth c. third 7 Actual Rate Law from a Table of Concentration/Rate Data 28. Given the following data, determine the rate law for the reaction NH4 +(aq) + NO2 –(aq) → N2(g) + 2H2O() Experiment [NH4 +] (M) [NO2 –] (M) Rate (M/s) 1 0.2500 0.2500 1.25 × 10–3 2 0.5000 0.2500 2.50 × 10–3 3 0.2500 0.1250 6.25 × 10–4 a. k[NH4 +][NO2 –] d. k[NH4 +]1/2[NO2 –]2 b. k[NH4 +]2[NO2 –] e. k[NH4 +][NO2 –]2 c. k[NH4 +][NO2 –]1/2 29. Given the following data, determine the rate law for the reaction 2NO(g) + Cl2(g) → 2NOCl(g) Experiment [NO] (M) [Cl2] (M) Rate (M/s) 1 0.0300 0.0100 3.4 × 10–4 2 0.0150 0.0100 8.5 × 10–5 3 0.0150 0.0400 3.4 × 10–4 a. Rate = k[NO][Cl2] d. Rate = k[NO]2[Cl2]2 b. Rate = k[NO][Cl2]2 e. Rate = k[NO][Cl2]1/2 c. Rate = k[NO]2[Cl2] 30. What is the rate law for the reaction 2A + 2B + 2C à products Initial [A] Initial [B] Initial [C] rate 0.273 0.763 0.400 3.0 0.819 0.763 0.400 9.0 0.273 1.526 0.400 12.0 0.273 0.763 0.800 6.0 a. rate = k[A][B][C] b. rate = k[A][B]2[C] c. rate = k[A]3[B]4[C]2 d. rate = k[A]2[B]2[C]2 10 Reaction Energy Diagrams, Activation Energy, Transition States… 41. Which point as labeled by an asterisk (*) on the following energy profile is the transition state? a. c. b. d. 42. The energy profiles for four different reactions are shown. Which reaction requires the most energetic collisions to reach the transition state? a. a c. c b. b d. d 11 43. The following energy profiles for four different reactions are shown. Which reaction is the most endothermic? a. a c. c b. b d. d 44. The following energy profiles for four different reactions are shown. Which reaction is the most exothermic? a. a c. c b. b d. d 45. Collision theory assumes that the rate of a reaction depends on __________ a. the energy of collisions. b. the orientation of colliding molecules. c. the energy of collisions and the orientation of colliding molecules. d. the change in energy between the products and the reactants. e. the change in free energy between the reactants and products. 12 46. The energy needed for a reaction to proceed from reactants to products is called __________ a. collision energy. d. potential energy. b. kinetic energy. e. thermodynamic energy. c. activation energy. 47. For the reaction diagram shown, which of the following statements is true? a. Line W represents the ∆H for the forward reaction; point B represents the transition state b. Line W represents the activation energy for the forward reaction; point B represents the transition state c. Line Y represents the activation energy for the forward reaction; point C represents the transition state d. Line X represents the ∆H for the forward reaction; point B represents the transition state Reaction Mechanisms, Intermediates… 48. A proposed mechanism for the photodecomposition of ozone in the atmosphere is Step 1: O3(g) + hν → O2(g) + O(g) Step 2: O3(g) + O(g) → 2 O2(g) Which of the following species is an intermediate? a. O3 d. O b. hν e. This mechanism has no intermediates. c. O2 49. A proposed mechanism for the decomposition of ozone in the atmosphere is Step 1: Cl(g) + O3(g) → ClO(g) + O2(g) Step 2: ClO(g) + O3(g) → Cl(g) + 2 O2(g) Which of the following species is an intermediate? a. Cl d. O2 b. O3 e. This mechanism has no intermediates. c. ClO 50. The reaction NO2(g) + CO(g) → NO(g) + CO2(g) is thought to occur by the following mechanism: Step 1: NO2(g) + NO2(g) → NO3(g) + NO(g) Step 2: NO3(g) + CO(g) → NO2(g) + CO2(g) Which of the following species is an intermediate? a. NO2 d. CO2 b. NO e. This mechanism has no intermediates. c. NO3 A B C Energy Extent of Reaction W X Y Z