Test: Reaction Kinetics (Chapter 11)

Multiple Choice Questions

  1. 1. Reaction kinetics is primarily concerned with:

  2. 2. Which of the following reactions is typically very rapid?

  3. 3. In a multi-step reaction, the overall rate is determined by:

  4. 4. The rate of a reaction is defined as:

  5. 5. The units for the rate of reaction are typically:

  6. 6. How does the rate of reaction generally change as the reaction proceeds?

  7. 7. The rate of reaction at a specific moment in time is called the:

  8. 8. In the rate expression Rate = -d[A]/dt = +d[B]/dt for A -> B, the negative sign indicates:

  9. 9. The Law of Mass Action states that the rate of reaction is proportional to:

  10. 10. In the rate equation Rate = k[A]ᵃ[B]ᵇ, 'k' represents the:

  11. 11. The specific rate constant 'k' is equal to the rate of reaction when:

  12. 12. The overall order of the reaction aA + bB -> cC + dD, with rate equation Rate = k[A]ᵃ[B]ᵇ is:

  13. 13. How is the order of a reaction determined?

  14. 14. The decomposition of N₂O₅ (2N₂O₅ -> 2N₂O₄ + O₂) has the rate equation Rate = k[N₂O₅]. What is the order of this reaction?

  15. 15. The hydrolysis of tertiary butyl bromide ((CH₃)₃CBr + H₂O -> (CH₃)₃COH + HBr) has the rate equation Rate = k[(CH₃)₃CBr]. This type of reaction is called:

  16. 16. The reaction NO(g) + O₃(g) -> NO₂(g) + O₂(g) has the rate equation Rate = k[NO][O₃]. What is the overall order?

  17. 17. The reaction 2FeCl₃(aq) + 6KI(aq) -> Products has the experimental rate equation Rate = k[FeCl₃][KI]². What is the overall order?

  18. 18. The reaction CHCl₃(l) + Cl₂(g) -> CCl₄(l) + HCl(g) has the rate equation Rate = k[CHCl₃][Cl₂]¹ᐟ². What is the overall order?

  19. 19. A reaction whose rate is entirely independent of the concentration of reactant molecules is said to be:

  20. 20. Photochemical reactions are often:

  21. 21. The half-life period (t₁ᐟ₂) of a reaction is defined as the time required to:

  22. 22. For a first-order reaction, the half-life period is:

  23. 23. The half-life for the decomposition of N₂O₅ at 45°C is 24 minutes. After 48 minutes, what percentage of N₂O₅ will remain unreacted?

  24. 24. For a second-order reaction, the half-life period is:

  25. 25. For a third-order reaction, the half-life period is:

  26. 26. In general, for a reaction of nth order, the half-life period [t₁ᐟ₂]n is proportional to:

  27. 27. If a reaction occurs in several steps, the rate determining step is:

  28. 28. In the reaction NO₂(g) + CO(g) -> NO(g) + CO₂(g), the experimental rate law is Rate = k[NO₂]². This implies:

  29. 29. In the proposed mechanism for NO₂(g) + CO(g) -> NO(g) + CO₂(g), what is the reaction intermediate?

  30. 30. A reaction intermediate is best described as:

  31. 31. Determining the rate of a chemical reaction typically involves measuring:

  32. 32. When plotting concentration of a reactant versus time, the curve obtained is typically:

  33. 33. How can the instantaneous rate of reaction be determined from a concentration-time graph?

  34. 34. Spectrometry can be used to measure reaction rates if:

  35. 35. The electrical conductivity method is suitable for reactions involving:

  36. 36. The dilatometric method measures changes in:

  37. 37. Optical rotation method is used when a reactant or product is:

  38. 38. In the chemical method for studying the hydrolysis of ethyl acetate, what is typically titrated against a standard alkali?

  39. 39. Why is the hydrolysis of ethyl acetate considered a pseudo first order reaction?

  40. 40. For a collision between reactant particles to be effective, the particles must possess:

  41. 41. The minimum amount of energy required for an effective collision is called:

  42. 42. The activated complex (or transition state) is:

  43. 43. On a potential energy diagram for a reaction, the activation energy (Ea) appears as:

  44. 44. In an exothermic reaction:

  45. 45. In an endothermic reaction:

  46. 46. The heat of reaction (ΔH) is equal to:

  47. 47. For an exothermic reaction, the activation energy for the forward reaction (Ea,fwd) compared to the backward reaction (Ea,rev) is:

  48. 48. The half-life method for determining reaction order relies on the relationship:

  49. 49. To determine the order 'n' using the half-life method, you need at least:

  50. 50. In the method of large excess, how is the order with respect to one reactant determined?

  51. 51. The method of large excess is particularly useful for determining the order of reactions like:

  52. 52. The rate of reaction depends on the 'nature of reactants' primarily due to differences in:

  53. 53. Ionic reactions (like neutralization or double decomposition) are generally:

  54. 54. Increasing the concentration of reactants generally increases the reaction rate because:

  55. 55. For the reaction 2NO(g) + 2H₂(g) -> 2H₂O(g) + N₂(g), if doubling [H₂] doubles the rate, the reaction is ___ order with respect to H₂.

  56. 56. For the reaction 2NO(g) + 2H₂(g) -> 2H₂O(g) + N₂(g), if doubling [NO] increases the rate four times, the reaction is ___ order with respect to NO.

  57. 57. Based on the experimental data for 2NO + 2H₂ -> Products, the overall order of the reaction is:

  58. 58. Increasing the surface area of a solid reactant increases the reaction rate because:

  59. 59. Which reaction rate is significantly affected by light?

  60. 60. According to collision theory, increasing temperature increases reaction rate primarily because:

  61. 61. As a general rule of thumb, for many reactions, the rate approximately doubles for every ___ rise in temperature.

  62. 62. The Arrhenius equation relates the rate constant 'k' to:

  63. 63. In the Arrhenius equation, k = Ae⁻ᴱᵃ/ᴿᵀ, 'A' represents:

  64. 64. The Arrhenius equation shows that the rate constant 'k' increases when:

  65. 65. Reactions with high activation energies tend to have:

  66. 66. The linear form of the Arrhenius equation is ln k = -Ea/RT + ln A. A plot of ln k versus ___ gives a straight line.

  67. 67. The slope of the Arrhenius plot (ln k vs 1/T) is equal to:

  68. 68. If the slope of an Arrhenius plot (log k vs 1/T) is -5400 K, what is the activation energy (Ea)? (R = 8.314 J K⁻¹ mol⁻¹)

  69. 69. A catalyst is a substance that:

  70. 70. How does a catalyst increase the rate of reaction?

  71. 71. In homogeneous catalysis:

  72. 72. The use of NO(g) in the lead chamber process for H₂SO₄ manufacture (2SO₂ + O₂ -> 2SO₃) is an example of:

  73. 73. In heterogeneous catalysis:

  74. 74. The hydrogenation of vegetable oils using finely divided Nickel is an example of:

  75. 75. Which statement about catalysts is generally TRUE?

  76. 76. A catalyst helps a reversible reaction to:

  77. 77. A substance that decreases the efficiency of a catalyst is called:

  78. 78. Traces of arsenic acting on a platinum catalyst in the contact process is an example of:

  79. 79. A substance that enhances the activity of a catalyst is called:

  80. 80. In the Haber process for ammonia synthesis (N₂ + 3H₂ -> 2NH₃), iron is the catalyst. Aluminum oxide added to iron acts as:

  81. 81. Negative catalysis refers to:

  82. 82. Tetraethyl lead added to petrol acts as:

  83. 83. Autocatalysis occurs when:

  84. 84. The reaction between oxalic acid and acidified KMnO₄ speeds up as MnSO₄ is formed. This is an example of:

  85. 85. Enzymes are biological catalysts that are typically:

  86. 86. The hydrolysis of urea into NH₃ and CO₂ is catalyzed by the enzyme:

  87. 87. The conversion of glucose into ethanol is catalyzed by the enzyme:

  88. 88. The 'lock and key' model describes the interaction between:

  89. 89. Which characteristic is typical of enzyme catalysis?

  90. 90. Enzyme activity is often highest at a specific pH and temperature, known as the:

  91. 91. A co-enzyme or activator typically:

  92. 92. Which physical method relies on changes in the bending of light as reaction proceeds?

  93. 93. In the rate equation Rate = k[A]ᵃ[B]ᵇ, the exponent 'a' represents:

  94. 94. If the half-life of a reaction is independent of the initial concentration, the reaction order is:

  95. 95. Which factor does NOT typically affect the rate constant 'k'?

  96. 96. The energy difference between reactants and the activated complex is:

  97. 97. The energy difference between products and the activated complex is:

  98. 98. Which method involves stopping the reaction at intervals by dilution and chilling?

  99. 99. The units of the rate constant for a first-order reaction are:

  100. 100. The units of the rate constant for a second-order reaction are:

  101. 101. The units of the rate constant for a third-order reaction are:

  102. 102. The units of the rate constant for a zero-order reaction are:

  103. 103. If a reaction rate doubles when concentration of reactant A is doubled, and quadruples when concentration of reactant B is doubled, the rate law is:

  104. 104. Moisture acting as a catalyst for the reaction between dry HCl and NH₃ is an example of needing only:

  105. 105. The Arrhenius constant 'A' is related to:

  106. 106. In the hydrolysis of an ester using an acid catalyst, the acid is:

  107. 107. Which factor primarily affects the *energy* of collisions?

  108. 108. Which factor primarily affects the *frequency* of collisions?

  109. 109. A catalyst affects the rate by changing the:

  110. 110. The decomposition of H₂O₂ can be catalyzed by colloidal platinum. This is:

  111. 111. The study of reaction rates helps in determining:

  112. 112. If two different initial concentrations a₁ and a₂ have half-lives t₁ and t₂, the order 'n' can be found using the ratio:

  113. 113. The reaction 4NH₃(g) + 5O₂(g) --Pt--> 4NO(g) + 6H₂O(g) is an example of:

  114. 114. Enzymes typically function best under specific conditions of:

  115. 115. The conversion of sugar (C₁₂H₂₂O₁₁) into glucose and fructose is catalyzed by:

  116. 116. The term 'active sites' is commonly associated with:

  117. 117. Which physical method would be suitable for studying the rate of reaction involving rotation of plane-polarized light?

  118. 118. A reaction A + B -> C is found to be first order in A and zero order in B. The rate law is:

  119. 119. For the reaction 2HI -> H₂ + I₂, the rate law is Rate = k[HI]². What happens to the rate if the concentration of HI is tripled?

  120. 120. The concept that reacting molecules must collide with sufficient energy and proper alignment is part of:

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Short Answer Questions

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