28 102 Sample Test 1 CHAPTER 13 1) What is the overall order of a reaction ( A + B --> C ) with the following rate law? rate = [A][B]2 a. first b. second c. third d. fourth 2) When a doubling of a reactant concentration doubles the rate, the reaction is said to be: a. zero order in that reactant. b. first order in that reactant. c. second order in that reactant. d. fourth order in that reactant. e. cannot be determined from the data given. 3) For the reaction A --> B the rate law is: rate = k[A]2 where k = 1x10-5 L mol-1 s-1. The rate of the reaction of A when the [A] is 0.10 molar is: a. 1 x 10-6 mol L-1 s-1 b. 1 x 10-7 mol L-1 s-1 -8 -1 -1 c. 1 x 10 mol L s d. 1 x 10-12 mol L-1 s-1 4) The half-life of a radioactive isotope is 10 days. How many days would be required for the isotope to degrade to one eighth of its original radioactivity? a. 20 b. 30 c. 3.33 d. 2.5 e. 80 5) Dust suspended in the air in grain elevators can sometimes explode because: a. the tiny dust particles will result in a very high surface area. b. the dust particles have a very flammable material. c. flammable gases are always present in the elevators. d. of the high temperatures always present in the elevators. e. of the constant sources of ignition. 6) Determine the rate equation for the hypothetical reaction A + B --> C given the following initial concentrations and initial rate data. Run # (1) (2) (3) [B]o [A]o 0.0020 0.0010 0.0040 0.0010 0.0020 0.0020 Initial Rate 2.80 x 10-5 1.12 x 10-4 5.60 x 10-5 a. rate = k [A]2[B] 2 b. rate = k [A]1[B] 2 c. rate = k [A] 2 [B]1 d. rate = k [A]1[B]1 7) Which of the following statement(s) is TRUE for a catalyst? a. decreases the rate of a reaction. b. undergoes a chemical change after a reaction. c. speeds up rate of a reaction without being consumed. d. pepsin, a digestive enzyme, is not considered as a catalyst. e. none of these 8) The reaction [ 2 N2O5 (g) ---> 4 NO2 (g) + O2 (g) ] is first-order in N2O5 . For this reaction the rate constant k = 1.0 x 10-5 s-1. If the initial concentration ([N2O5]o ) of N2O5 is equal to 1.0 x 10-3 M, calculate [N2O5] after 1.0 x 105 seconds. a. 5.0 x 10-4 M b. 2.0 x 10-3 M c. 3.7 x 10-4 M d. 0 e. none of these 9) What are the units of a rate constant (k) in a second order rate equation? a. L2/mol2 s b. L/mol s c. 1/s d. L3/mol3 s e. s 10) The reaction A ---> B + C is known to follow the rate law: rate = k [A]1 what is the integrated rate law for this reaction? a. [A] = kt b. [A]t - [A]o = kt c. [A]t/[A]o = kt d. ln A]t/[A]o = - kt e. [A]o- [A]t = kt 11) Given the following initial rate data for the reaction in aqueous solution determine the rate law. CH3COCH3 + Br2 --H+--> CH3COCH2Br + H+ + Br[CH3COCH3]0 1.00 2.00 2.00 1.00 [Br2]0 1.00 1.00 2.00 2.00 [H+]0 1.00 1.00 1.00 2.00 ∆[Br2]/ ∆t(M/s) 4.0 x 10-3 8.0 x 10-3 8.0 x 10-3 8.0 x 10-3 a) Rate = k[Br2][H+] b) Rate = k[CH3COCH3][Br2] c) Rate = k[CH3COCH3][H+] + + 2 d) Rate = k[CH3COCH3][Br2][H ] e) Rate = k[CH3COCH3][Br2][H ] 12) For the reaction A ---> Products, successive half-lives are observed to be 10.0 min, and 20.0 min. At the beginning of the reaction, [A] was 0.10 M. The numerical value of the rate constant is 29 a) 0.069 b) 1.0 c) 10.0 d) 5.0 x 10 e) none of these 13) For the reaction, 2N2O5(g) ---> 4NO2(g) + O2(g), the following data were collected: (hint: reaction follows first order rate law and calculate k, the rate constant and use ln [A]0/[A]t = kt) t(minutes) [N2O5](mol/L) 0. 1.24 x 10-2 10. 0.92 x 10-2 20. 0.68 x 10-2 30. 0.50 x 10-2 40. 0.37 x 10-2 50. 0.28 x 10-2 70. 0.15 x 10-2 The concentration of N2O5 at 100 minutes will be approximately a) 0.03 x 10-2 mol/L b) 0.06 x 10-2 mol/L c) 0.10 x 10-2 mol/L d) 0.01 x 10-2 mol/L e) none of these 14) When a doubling of a reactant concentration doubles the rate, the reaction is said to be: a. zero order in that reactant. b. first order in that reactant. c. second order in that reactant. d. fourth order in that reactant. e. cannot b e determined from the data given. 15) For the reaction A --> B the rate law is: rate = k[A]2 where k = 1x10-5 L mol-1 s-1. The rate of the reaction of A when the [A] is 0.10 molar is: a. 1 x 10-6 mol L-1 s-1 b. 1 x 10-7 mol L-1 s-1 c. 1 x 10-8 mol L-1 s-1 d. 1 x 10-12 mol L-1 s-1 -13 -1 -1 e. 1 x 10 mol L s 16) The following chemical reaction gave the following rate data: A + B ---> C initial conc.(mol L-1) initial rate of formation [A] [B] of C (mol L-1 s-1) 0.20 0.20 1 x 10-6 0.40 0.20 4 x 10-6 0.40 0.40 8 x 10-6 The rate law for this reaction is: a. rate = k [A]2[B] 2 b. rate = k [A] 2 [B] 4 4 c. rate = k [A] [B] d. rate = k [A][B] e. rate = k [A][B] 2 17) The half-life of a radioactive isotope is 10 days. How many days would be required for the isotope to degrade to one eighth of its original radioactivity? a. 20 b. 30 c. 3.33 d. 2.5 e. 80 18) Dust suspended in the air in grain elevators can sometimes explode because: a. the tiny dust particles will result in a very high surface area. b. the dust particles have a very flammable material. c. flammable gases are always present in the elevators. d. of the high temperatures always present in the elevators. e. of the constant sources of ignition. 19) Determine the rate equation for the hypothetical reaction A + B --> C given the following initial concentrations and initial rate data. Run # [A]o [B]o Initial Rate mol/L) (mol/L) (mol/L s) -------------------------------------------(1) 0.0020 0.0010 2.80 x 10-5 (2) 0.0040 0.0010 1.12 x 10-4 (3) 0.0020 0.0020 5.60 x 10-5 -------------------------------------------b. rate = k [A]1[B]2 c. rate = k [A]2[B]1 d. rate = k [A]1[B]1 a. rate = k [A]2[B]2 20) Which of the following statement(s) is TRUE for a catalyst? a. decreases the rate of a reaction. b. undergoes a chemical change after a reaction. c. speeds up rate of a reaction without being consumed. d. pepsin, a digestive enzyme, is not considered as a catalyst. e. none of these 21) The reaction [ 2 N2O5 (g) ---> 4 NO2 (g) + O2 (g) ] is first-order in N2O5. For this reaction the rate constant k = 1.0 x 10-5 s-1. If the initial concentration ([N2O5]o ) of N2O5 is equal to 1.0 x 10-3 M, calculate [N2O5] after 1.0 x 105 seconds. a. 5.0 x 10-4 M b. 2.0 x 10-3 M c. 3.7 x 10-4 M 30 d. 0 e. none of these 22. What are the units of a rate constant (k) in a second order rate equation? a. L2/mol2 s b. L/mol s c. 1/s d. L3/mol3 s e. s 23. What is the overall order of a reaction if it has following rate law? a. first b. second c. third d. fourth rate = k [NO] [N2] [O2] 24. The equation and the rate law for the reaction between NO(g) and H2(g) are 2NO(g) + 2H2(g) ---> N2(g) + 2H2O(g) Rate = k[NO]2[H2] The overall reaction order is a. 0. b. 1. c. 2. d. 3. e. 4. 25. The reaction CO + Cl2 ---> COCl + Cl is first order in CO and second order in Cl2. Which is the rate law? a. rate = k[CO]1[COCl]2 b. rate = k[COCl]1[Cl]2 c. rate = k[CO]1[Cl2]1 d. rate = k[CO]1[Cl2]2 e. rate = k[CO]2[Cl2]2 26. For the following chemical raction: N2 (g) + 3 H2 (g) --> 2 NH3 (g) The rate of disapperance of N2 is found to be 2.4 x 10-5 mol/L s. What is the rate of formation of NH3 ? a. 2.4 x 10-5 mol/L s b. 4.8 x 10-4 mol/L s c. 4.8 x 10-5 mol/L s d. 5.0 x 10-2 mol/L s e. none of these 27. If the rate law for a reaction is third order, What are the units of k when time is in seconds and the concentration is in moles per liter? a. mol/L s b. L s/mol c. mol2/L2 s d. L2/mol2 s e. L3/mol3 s 28. The reaction A ---> B + C is known to follow the rate law: rate = k [A]1 what is the integrated rate law for this reaction? 29. Determine the rate equation for the hypothetical reaction A + B --> C given the following initial concentrations and initial rate data. Run # [A] [B] Initial Rate (mol/L) (mol/L) (mol/L s) --------------------------------------------------(1) 0.0020 0.0010 2.80 x 10-5 (2) 0.0040 0.0010 1.12 x 10-4 (3) 0.0020 0.0020 5.60 x 10-5 --------------------------------------------------a. rate = k [A]2[B]2 b. rate = k [A] [B]2 c. rate = k [A]2[B] d. rate = k [A] [B] 30. The reaction [ 2 N2O5 (g) ---> 4 NO2 (g) + O2 (g) ] is first-order in N2O5 . For this reaction the rate constant k = 1.0 x 10-5 s-1. If the initial concentration ([N2O5]o ) of N2O5 is equal to 1.0 x 10-3 M, calculate [N2O5] after 1.0 x 105 seconds. a. 5.0 x 10-4 M b. 2.0 x 10-3 M c. 3.7 x 10-4 M 32. Consider the following reaction and the kinetic data: CO + Cl2 ---> COCl + Cl d. 0 e. none of these rate law: rate = k[CO]1[Cl2]2 [CO]o(mol/L) [Cl2]o (mol/L) Rate (mol/L s) --------------------------------------------1.00 x 102 1.00 x 102 6.60 x 103 2 2 2.00 x 10 1.00 x 10 1.32 x 104 2 2 3.00 x 10 1.00 x 10 1.98 x 104 2 2 1.00 x 10 2.00 x 10 2.64 x 104 2 2 3.00 x 10 1.19 x 105 2.00 x 10 ---------------------------------------------What is the rate constant (k) for the reaction? a. 1.0 x 10-2 L2 /mol2 s b. 3.0 x 102 L2 /mol2 s 2 2 2 e. 2.0 x 10 L /mol s 31 c. 6.6 x 10-3 L2 /mol2 s d. 3.3 x 10-3 L2 /mol2 s 33. Which of the five factors listed does not affect the rate of a homogeneous reaction? a. the presence of catalysts b. the concentrations of reactants c. the temperature of the reaction system d. the surface area of the reactants e. the properties of the reactants and the products 34. Which unit is appropriate for describing reaction rates? a. mol L-1 min-1 b. g L-1 c. kJ mol-1 d. kJ g-1 e. °C min-1 35. A negative sign is included in the expression for the rate of disappearance of a reactant because a. the value of ∆[reactant] is positive as calculated b. reaction rate is defined as a positive quantity c. it cancels out the negative value of ∆t in the denominator d. the change in concentration can never be zero e. the coefficients in the balanced equation can never be negative 36. Which statement about rate constants is not correct? a. Its value is independent of the concentration of the reactant(s). b. Its value generally increases as temperature increases. c. It has the same value for all reactions at a particular temperature. d. It is symbolized by "x." e. It always includes units of time. 37. Which statement describes a correct approach to determining the rate law for a reaction? a. Balance the chemical equation and use the coefficients of the reactants as exponents for the concentrations of reactants. b. Balance the chemical equation and use the coefficients of the reactants as factors for the concentrations. c. Balance the chemical equation and use the reciprocals of the coefficients of the reactants as factors for the concentrations. d. Perform experiments in which the initial rate of the reaction is measured using varying amounts of each reactant. e. Perform experiments in which the concentration of each reactant is measured at specific time intervals. 38. For the reaction between water and a complex ion of Co2+, the rate varies with concentration as follows (The rate has no dependance on [H2O]): Trial 1 2 3 4 [Co2+ complex] M 1.14 × 10-3 2.28 × 10-3 3.42 × 10-3 1.14 × 10-2 The rate law for the reaction is rate = a. k[Co2+ complex] Initial rate M min-1 3.2 × 10-7 6.4 × 10-7 9.6 × 10-7 3.2 × 10-6 b. k[Co2+ complex]2 c. 2k[Co2+ complex] d. k2[Co2+ complex] e. 5k[Co2+ complex] 39. For the reaction between water and a complex ion of Co2+, the rate varies with concentration as follows (The rate has no dependance on [H2O]): Trial 1 2 3 4 [Co2+ complex] M 1.14 × 10-3 2.28 × 10-3 3.42 × 10-3 1.14 × 10-2 32 Initial rate M min-1 3.2 × 10-7 6.4 × 10-7 9.6 × 10-7 3.2 × 10-6 Calculate the value of the rate constant. a. 3.6 × 10-6 min-1 b. 2.8 × 10-4 min-1 c. 4.6 × 103 min-1 d. 1.1 × 10-3 min-1 e. 1.1 × 10-2 min-1 40. The rate law for a given reaction is rate = k[reactant], with k = 2.64 × 10-4 min-1. If the initial concentration is 0.0250 M, what is the initial rate? a. 94.7 M min-1 b. 1.06 × 10-2 M min-1 c. 2.53 × 10-2 M min-1 d. 2.47 × 10-2 M min-1 e. 6.60 × 10-6 M min-1 41. Consider the reaction A + 2B → 2C + D, where the rate law is rate = k[B]2. This reaction is _____ order with respect to A, _____ order with respect to B, and _____ order overall. a. first; second; third b. zero; second; third c. zero; second; second d. first; first; second e. second; zero; second 42. Consider the reaction NO2 + O3 → NO3 + O2 Use the data shown to determine the rate law for the reaction. a. rate = k[NO2]2[O3] b. rate = k[NO2][O3]2 c. rate = k[NO2][O3] d. rate = k[NO3][O3] e. rate = k[NO3][O3]/[NO2][O3] 43. A certain reaction is studied at room temperature, and gives a straight line plot for 1/[reactant] versus time. If a similar experiment is performed at 40°C, how will the two graphs differ? a. They will be identical. b. The graph at the higher temperature will be parallel to the original graph, with a larger value for the y-intercept. c. The graph at the higher temperature will be parallel to the original graph, with a smaller value for the y-intercept. d. The graph at the higher temperature will be a steeper line, but have the same y-intercept. e. The graph of ln[reactant] versus time will be a straight line. 33 44. The data from a kinetics experiment is plotted, giving a straight line for the plot of ln[reactant] versus time. From this information we can conclude that the reaction is _____ order and that the rate law is rate = _____. a. zero; 2k[reactant] b. first; k[reactant] c. second; k[reactant] d. second; 2k[reactant] e. second; k[reactant]2 45. The data from a kinetics experiment is plotted, giving a straight line for the plot of 1/[reactant] versus time. From this information we can conclude that the reaction is _____ order and that the rate law is rate = _____. a. first; 2k[reactant] b. first; k[reactant] c. second; k[reactant] d. second; 2k[reactant] e. second; k[reactant]2 46. The rate constant for the first-order conversion of A to B is 2.22 hr-1. How much time will be required for the concentration of A to reach 75% of its original value? a. 2.2 hr b. 1.6 hr c. 37 min d. 27 min e. 7.8 min 47. The rate constant for the first-order conversion of A to B is 2.22 hr-1. What is the half-life of the reaction? a. 0.312 hr b. 0.465 hr c. 1.54 hr d. 2.22 hr e. 3.20 hr 48. The rate constant for the first order decomposition of SO2Cl2 at a very high temperature is 1.37 × 10-3 min-1. If the initial concentration is 0.500 M, predict the concentration after five hours (300 min). a. 0.500 M b. 6.85 × 10-4 M c. 0.331 M d. 1.33 M e. 0.754 M 49. When the structure of only one atom, molecule or ion is rearranged to produce a new species, the process is called a(an) a. activated complex b. activation energy c. bimolecular reaction d. steric factor e. unimolecular reaction 50. When two particles must collide to produce a new species, the process is called a(an) a. activated complex b. activation energy c. bimolecular reaction d. steric factor e. unimolecular reaction 51. The species representing the combination of atoms or molecules at the top of the energy barrier is called the a. activated complex b. activation energy c. bimolecular reaction d. steric factor e. unimolecular reaction 52. In a bimolecular reaction, the _____ describes the spatial orientation that is necessary in order for the chemical reaction to occur. a. activation energy b. frequency factor c. probability d. steric factor e. pre-exponential factor 53.The Arrhenius equation is a. E = mc2 b. PV = nRT 34 54. 55. 56. 57. 58. 59. c. M1V1 = M2V2 d. rate = k[reactant]2 e. k = Ae-Ea/RT The frequency factor in the Arrhenius equation can best be described as a. a numerical description of how often molecules collide with the proper orientation to react at a specific concentration. b. a numerical description of the amount of energy needed by colliding reactant molecules in order to form products. c. a numerical description of the amount of energy released by colliding reactant molecules when they form products. d. the base of the natural logarithm system. e. a factor which corrects for the conversion between J and kJ. The activation energy in the Arrhenius equation can best be described as a. a numerical description of how often molecules collide with the proper orientation to react at a specific concentration. b. a numerical description of the amount of energy needed by colliding reactant molecules in order to form products. c. a numerical description of the amount of energy released by colliding reactant molecules when they form products. d. the base of the natural logarithm system. e. a factor which corrects for the conversion between J and kJ. In order to determine the value of the activation energy for a particular chemical reaction, a. at least two experiments at the same temperature, but varying concentrations of each reactant, must be performed. b. the reaction mechanism must be experimentally verified. c. the rate law must be determined. d. the reaction must be a first order reaction. e. at least two experiments to determine the value of the rate constant at different temperatures must be performed. If the rate law for an elementary step is first order, we can conclude that a. the elementary step is bimolecular. b. the elementary step is unimolecular. c. additional experiments at different temperatures are needed to determine the molecularity of that step. d. no catalysts are involved in the step. e. no intermediates are formed in that step. If the rate law for an elementary step is second order, we can conclude that a. the elementary step involves a collision between two molecules. b. the elementary step is unimolecular. c. additional experiments at different temperatures are needed to determine the molecularity of that step. d. no catalysts are involved in the step. e. no intermediates are formed in that step. A reaction mechanism is a a. list of all the possible steps by which a reaction might occur on the nano scale. b. Series of elementary steps which add up to the overall chemical reaction under consideration. c. description of the relationship between the rate of a reaction and the concentrations of all species. d. description of the relationship between the rate of a reaction and the temperature at which it occurs. e. detailed description of the characteristics of the activated complex in a reaction. For the following questions, consider the following reaction mechanism: Step 1 Step 2 Step 3 2X W V + + + Y Z Z → → → W W 2W 60. The intermediates in this reaction are a. X and Y b. W and Y c. Z and V d. Y only + + + 2Z U Y + V fast slow fast 35 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. e. There are no intermediates in this reaction. The catalysts in this reaction are a. X and Y b. W and Y c. Z and V d. Y only e. There are no catalysts in this reaction. The overall reaction described by this mechanism is a. 2X + Y → W + 2Z b. W + Z → W + U + V c. V + Z → 2W + Y d. X + Z + Y → U + W e. 2X → 3W + U The rate-limiting step in this reaction is Step _____, because _____. a. 1; the first step must occur before any others can occur b. 1; it is bimolecular c. 2; it is the slow step d. 2; it uses a product of the first step e. 3; the last step is always the rate-limiting step A reaction intermediate is a. always a reactant in the rate-limiting step. b. a species that is produced in an early step and consumed in a later step. c. a species that is consumed in an early step and regenerated in a later step. d. always a product in the last step of a mechanism. e. a species that is in a different phase than the other reactants. Which of the following factors increases the rate of a chemical reaction by increasing the number of molecules with enough energy to overcome the activation energy barrier? a. increasing the temperature b. increasing the concentration of reactants c. increasing the concentration of products d. adding a catalyst e. increasing the surface area of a phase interface Which of the following factors increases the rate of a chemical reaction by increasing the number of collisions between reactant molecules? a. increasing the temperature b. increasing the concentration of reactants c. increasing the concentration of products d. adding a catalyst e. decreasing the surface area of a phase interface Which of the following factors increases the rate of a chemical reaction by decreasing the activation energy barrier? a. increasing the temperature b. increasing the concentration of reactants c. increasing the concentration of products d. adding a catalyst e. increasing the surface area of a phase interface Which statement comparing a catalyzed and uncatalyzed reaction is incorrect? a. The initial and final energy states are the same. b. The reaction mechanisms are the same. c. The activation energy is higher in the uncatalyzed reaction. d. The balanced equation for the overall reaction is the same. e. The reaction progress diagrams are different. An enzyme is a(an) a. molecule that is acted on by a catalyst in a living system. b. organic or inorganic molecule or ion necessary for proper functioning of biological catalysts. c. catalyst for chemical reactions in a living system. d. biological molecule used for storage of energy. e. protein molecule whose primary function is transport of insoluble molecules in the bloodstream. A cofactor is a(an) a. molecule that is acted on by a catalyst. b. organic or inorganic molecule or ion necessary for proper functioning of some biological catalysts. c. catalyst for chemical reactions in a living system. 36 71. 72. 73. 74. 75. 76. 77. d. biological molecule used for storage of energy. e. protein molecule whose primary function is transport of insoluble molecules in the bloodstream. The best description of the induced fit model of enzyme function is a. a molecule not directly involved in the catalysis interacts with a site on the protein far from the active site, changing the shape of the active site to make it work. b. the active site has a definite, rigid shape that only fits one substrate molecule. c. a cofactor must first bind to the active site, allowing the substrate to fit properly. d. a short protein chain that blocks access to the active site is chemically removed as the substrate approaches. e. the active site, the substrate, or both change shape upon binding so that the activation energy of the desired change is decreased. Which factor is not a consideration in determining the effectiveness of an enzyme? a. the proximity effect, in which the enzyme brings two reactants near each other b. pH effects, in which the enzyme accepts or donates hydrogen ions to influence the reaction c. the presence of metal ions to catalyze redox reactions d. the identity of the solvent in which the reactants are dissolved e. the lowering of the potential energy barrier In an enzyme-catalyzed reaction when the reaction rate no longer increases as the concentration of substrate increases, but the reaction does continue to occur, the conclusion is that a. the enzyme has become the limiting reactant. b. the enzyme has been denatured. c. the enzyme has been inhibited. d. the enzyme has been hydrolyzed. e. the pH of the system has interfered with the reaction. The disruption of enzyme function that occurs when increased temperatures cause a change in the shape of the active site is called a. complex formation. b. denaturation. c. hydrolysis. d. induced fit. e. inhibition. A molecule that fits into the active site of an enzyme, but remains there instead of reacting and being released is called a(an) a. accelerator b. hydrolyzing agent c. inhibitor d. oxidizing agent e. reducing agent The solid catalysts used in many industrial processes where the reactants are liquids or gases are referred to as a. enzymes. b. heterogeneous catalysts. c. homogeneous catalysts. d. silicon catalysts. e. zeolites. The group of elements most likely to be found in catalysts for industrial use is a. C, H, N, O, S b. Rb, Cs, Sr, Ba c. Ne, Ar, Kr d. Rh, Pt, Pd e. Si, Ge, As, B Answers to the questions: 1. > c. third 2. > b. first order in that reactant. 3. > b. 1 x 10-7 mol L-1 s-1 4. > b. 30 5. > a. the tiny dust particles will result in a very high surface area. 6. > c. rate = k [A] 2 [B]1 7. > c. speeds up rate of a reaction without being consumed. 8. > c. 3.7 x 10-4 M 9. > b. L/mol s 10. > d. ln [A]t/[A]o = - kt 11. > c. Rate = k[CH3COCH3][H+] 12. > a. 0.0693 37 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. > > > > > > > > > > > > > > > > > > b. 0.06 x 10-2 mol/L b. first order in the recatan b. 1 x 10-7 mol L-1 s-1 b rate = k [A]2[B] b 30 days. a the tiny dust particles will result in a very high surface area. c rate = k [A]2[B]1 c peeds up rate of a raction without being consumed. c 3.7 x 10-4 M b L/mol s c third d3 d rate = k[CO]1[Cl2]2 c 4.8 x 10-5 mol/L s d L2/mol2 s d ln [A]t/[A]o= - kt c rate = k [A]2[B] c 3.7 x 10-4 M 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > c 6.6 10-3 L2 /mol2 s d. the surface area of the reactants a. mol l-1 min-1 b. reaction rate is defined as a positive quantity c. it is symbolized by "k." d. perform experiments in which the initial rate of the reaction is measured using varying amounts of each reactant. a. k[Co2+ complex] b. 2.8 × 10-4 min-1 e. 6.60 × 10-6 m min-1 c. zero; second; second c. rate = k[NO2][O3] d. the graph at the higher temperature will be a steeper line, but have the same y-intercept. b. first; k[reactant] e. second; k[reactant]2 e. 7.8 min a. 0.312 hr c. 0.331 M e. unimolecular reaction c. bimolecular reaction a. activated complex d. steric factor e. k = Ae-Ea/RT a. a numerical description of how often molecules collide with the proper orientation to react at a specific concentration. b. a numerical description of the amount of energy needed by colliding reactant molecules in order to form products. e. at least two experiments to determine the value of the rate constant at different temperatures must be performed. b. the elementary step is unimolecular. a. the elementary step involves a collision between two molecules. b. series of elementary steps which add up to the overall chemical reaction under consideration. c. Z and V d. Y only e. 2X → 3W + U c. 2; it is the slow step b. a species that is produced in an early step and consumed in a later step. a. increasing the temperature b. increasing the concentration of reactants d. adding a catalyst b. the reaction mechanisms are the same. c. catalyst for chemical reactions in a living system. b. organic or inorganic molecule or ion necessary for proper functioning of some biological catalysts. e. the active site, the substrate, or both change shape upon binding so that the activation energy of the d. the identity of the solvent in which the reactants are dissolved. a. the enzyme has become the limiting reactant. 38 74. 75. 76. 77. > > > > b. denaturation. c. inhibitor b. heterogeneous catalysts. d. Rh, Pt, Pd