1. The units of the rate of a reaction are _____.
A) mol L–1s–1
B) mol L–1
C) mol L s–1
D) L mol–1s–1
2. The ratio -∆[A]/∆t for a reaction A → B is called the _____.
A) overall rate
B) instantaneous rate
C) average rate
D) final rate
3. The most unambiguous quantity is _____.
A) overall rate
B) instantaneous rate
C) average rate
D) final rate
4. Which of the following reaction rates is the highest?
A) Initial rate
B) Average rate
C) Final rate
D) Instantaneous rate
5. The rate of the reaction H2 + I2 → 2HI is _____.
A)
B)
C)
D)
Page 1
6. The rate of the following reaction in terms of bromate is _____.
5Br¯(aq) + BrO3¯(aq) + 6H+(aq) → 3Br2(aq) + 3H2O(l)
A)
B)
C)
D)
7. The correct relation between the rates of the reaction: 2H2 + O2 → 2H2O is _____.
A)
B)
C)
D)
8. The rate of disappearance of NO in the reaction 2NO + O2 → 2NO2 is 0.066 Ms–1. The
rate of formation of NO2 is _____ Ms–1.
A) 0.066
B) 0.132
C) 0.033
D) 0.66
9. Nitric oxide in the reaction: 2NO + O2 → 2NO2 reacts at the rate of 0.066 Ms–1. The rate
at which O2 reacts is _____ Ms–1.
A) 0.132
B) 0.066
C) 0.264
D) 0.033
Page 2
10. The rate at which hydrogen reacts in the reaction N2 + 3H2 → 2NH3 is 0.074 Ms–1. The
rate of formation of ammonia is _____ Ms–1.
A) 0.148
B) 0.049
C) 0.111
D) 0.222
11. The rate of reaction of N2 in the reaction N2 + 3H2 → 2NH3 is 0.025Ms–1. The rate at
which hydrogen reacts will be _____ Ms–1
A) 0.075
B) 0.025
C) 0.050
D) 0.100
12. A rate law relates the rate of a reaction to _____.
A) concentration
B) order
C) rate constant
D) all of them
13. The order of a reaction is the power of the _____ term in the Rate Law.
A) rate
B) concentration
C) rate constant
D) molecularity
14. The rate constant units of a second-order reaction are _____.
A) Ms–1
B) Ms
C) M–1s–1
D) M–1
15. The order of a reaction having a rate constant 1.6 × 10–3 s–1 is _____.
A) one
B) three
C) two
D) zero
Page 3
16. The units of the rate constant of a zero-order reaction are _____.
A) s–1
B) zero
C) Ms–1
D) M–1s–1.
17. The rate is always constant for a _____ order reaction
A) first
B) zero
C) higher
D) lower
18. The reaction A → B is a zero-order reaction. The plot of rate vs [A] of the reaction is a
_____.
A) curve
B) straight line parallel to the x axis
C) straight line parallel to the y axis
D) straight line with a negative slope
19. The rate constant of a first-order reaction is 66.0 s–1. The value in min–1 is _____.
A) 66
B) 3.96 × 103
C) 3.96 × 10–3
D) 1.1
20. The rate constant depends on _____.
A) reactant concentrations
B) temperature
C) volume
D) mass of products
21. The Rate Law for the reaction NH4+(aq) + NO2– (aq) → N2(g) + 2H2O(l) is given by rate
= k[NH4+][NO2–]. The rate constant of the reaction is 3.0 × 10–4 M–1s–1. The rate of the
reaction when [NH4+] = 0.26 M and [NO2–] = 0.080 M is _____.
A) 6.2 × 10–6 Ms–1
B) 1.3 × 10–4 Ms–1
C) 2.4 × 10–8 Ms–1
D) 3.2 ×10–3 Ms–1
Page 4
22. The rate data for the reaction between F2 and ClO2 is
[ClO2],(M)
Initial Rate(M/s)
[F2],(M)
0.10
0.01
1.2 ×10–3
0.10
0.04
4.8 × 10–3
0.20
0.01
2.4 × 10–3
The order of the reaction with respect to ClO2 is _____.
A) 2
B) 4
C) 1
D) 3
23. The rate data for the reaction between F2 and ClO2 are:
[F2]
[ClO2]
Initial Rate, (M/s)
0.10
0.01
1.2 ×10–3
0.10
0.04
4.8 × 10–3
0.20
0.01
2.4 × 10–3
The reaction order with respect to F2 is _____.
A) 3
B) 1
C) 0
D) 2
24. The rate data for the reaction A +B→ Products are:
[A]
[B]
Rate(M/s)
1.50
1.50
3.20 × 10–1
1.50
2.50
3.20 × 10–1
3.00
1.50
6.40 × 10–1
The Rate Law of the reaction is _____.
A) rate = k [A][B]2
B) rate = k [A]
C) rate = k [A][B]
D) rate = k [B]
Page 5
25. Determine the rate constant for the reaction A +B→ Products from the following initial
rate data:
[A]
[B]
Rate(M/s)
1.50
1.50
3.20 × 10–1
1.50
2.50
3.20 × 10–1
3.00
1.50
6.40 × 10–1
The rate constant is _____.
A) 0.213 s–1
B) 0.0825 M–1s–1
C) 3.2 × 10–2 s–1
D) 0.525 s–1
26. The order of a reaction can be _____.
A) 1.5
B) –1
C) 0
D) all the above
27. The rate of the reaction A → B is 1.6 × 10–2 Ms–1 when the concentration of A is 0.350
M. What is the rate constant if the reaction is a first-order in A?
A) 0.046 s–1
B) 2.303 s–1
C) 0.46 s–1
D) 4.6 s–1
28. The rate of the reaction A → B when [A] = 0.35 M is 1.6 × 10–2 Ms–1. If the reaction is
second order in A, the rate constant is _____ M–1s–1.
A) 1.3
B) 2.6
C) 26
D) 0.13
29. The reaction A(g) → 2B(g) was found to be first-order in A. Which of the following
plots will be in a straight line?
A) ln [A ] vs t
B) [A ] vs t
C) ln [B] vs t
D) [B] vs t
Page 6
30. If [A]0 and [A]t are the concentrations of the reactant A at t = 0 and t = t, the correct
expression for the first-order reaction is _____.
A)
[A]t
ln
= − kt
[A]0
B)
[A]t
ln
= kt
[A]0
C) [A]t
= e kt
[A]0
D)
1 [A]t
k = ln
t [A]0
31. If [A]0 and [A]t are the concentration of the reactant A at t = 0 and t = t the correct
relation for the second-order reaction A → B is _____.
A)
1
1
=
+ kt
[A]0 [A]t
B)
1
1
=
+ kt
[A]t [A]0
C) [A]t = [A]0 + kt
D) 1
= [A]t + [A]0
kt
32. The correct relationship between half-life, t1/2, and the rate constant, k, for a first-order
reaction is given as t1/2 = _____.
A)
B)
C)
D)
Page 7
33. The correct relationship between half-life, t1/2,and the rate constant, k, for a secondorder reaction is given as _____.
A) t 1 = k[A]0
2
B)
2
C)
D)
k
[A]0
1
=
k[A]0
1
=
[A]0
t1 =
t1
t1
2
2
34. The correct statement is.
A) t1/2 is proportional to A0 for a first-order reaction
B) t1/2 is inversely proportional to A0 for a second-order reaction
C) t1/2 is proportional to A0 for a second-order reaction
D) t1/2 is inversely proportional to A0 for a first-order reaction
35. For a first order reaction the time needed for the initial concentration of the reactant to
fall to one-eighth of its original value is _____ times the t1/2.
A) 3
B) 8
C) 4
D) 2
36. What is the half-life for the reaction assuming first-order kinetics if 75% of a reactant
decomposes in 60 minutes?
A) 120 min
B) 15 min
C) 90 min
D) 30 min
37. The reaction 4PH3(g) → P4(g) + 6H2(g) is a first-order reaction with a half-life of 35 s.
The rate constant of the reaction is _____ s–1.
A) 1.12 × 10–4
B) 1.98 × 10–2
C) 1.98 × 10–3
D) 3.16 × 10–2
Page 8
38. The half-life of a first-order reaction is 35.0 s. The time required for 95.0% of the
reactant to decompose is _____.
A) 151 s
B) 89 s
C) 1600
D) 271
39. The rate constant of the second-order reaction 2NOBr(g) → 2NO(g) + Br2(g) is 0.80 M–
1 –1
s . Starting with a concentration of NOBr of 0.086 M, the concentration of NOBr after
22 seconds is _____.
A) 0.022 M
B) 0.076 M
C) 0.062 M
D) 0.034 M.
40. The half-life of a second-order reaction when [A]0 = 0.072 M was 25 minutes. The halflife when [A]0 = 0.036 M will be _____ minutes.
A) 50
B) 25
C) 12.5
D) 6.25
41. The rate constant of the reaction A → product is 0.54 M–1s–1. The time taken for the
concentration of A to decrease from 0.62 M to 0.28 M is _____ seconds.
A) 6.3
B) 21
C) 3.6
D) 15
42. The rate constant of a reaction increases with _____.
A) increase in activation energy
B) decrease in temperature
C) decrease in activation energy
D) increase in enthalpy
43. According to the Arrhenius equation, a plot of _____ is a straight line.
A) k vs. T
B) ln k vs. 1/T
C) ln k vs. ln T
D) k vs. 1/T
Page 9
44. A reaction at 250 °C is 1.50 × 103 times faster than at 150 °C. The activation energy of
the reaction is _____.
A) 135 kJ mol–1
B) 270 kJ mol–1
C) 31.0 kJ mol–1
D) 185 kJ mol–1
45. The frequency factor and energy of activation of a reaction are 8.7 × 1012 s–1 and 63 kJ
mol–1. The rate constant of the reaction at 75 °C is _____.
A) 7.2 × 10–2
B) 1.8 × 105
C) 5.4 × 10–3
D) 3.0 × 103 s–1
46. The rate constant of a reaction is 4.60 × 10–4 s–1 at 350 °C. The temperature at which the
rate constant will be 8.80 × 10–4 s-1 is _____. [The activation energy is 104 kJ mol–1].
A) 461 °C
B) 371 °C
C) 417 °C
D) 392 °C
47. The rate constant for a reaction at 305.0 K is two times the rate constant at 295.0 K. The
activation energy of the reaction is _____ kJ mol–1.
A) 36.2
B) 21.7
C) 72.9
D) 51.8
48. Which of the following is a theoretical concept?
A) order
B) molecularity
C) rate
D) rate constant
49. The molecularity of the elementary reaction CH3NC → CH3CN is _____.
A) six
B) two
C) zero
D) one
Page 10
50. Which of the following reactions are rare?
A) unimolecular
B) zero order
C) exothermic
D) termolecular
51. The rate determining step is the ______.
A) slow step
B) first step
C) fast step
D) step giving the product
52. Which of the following cannot be isolated in a reaction?
A) intermediate
B) product
C) activated complex
D) reactant
53. The reaction 2 NO + Cl2 → 2NOCl is thought to follow the mechanism:
NO + Cl2 → NOCl2 (slow)
NOCl2 + NO → 2NOCl (fast).
The Rate Law of the reaction is ______.
A) rate = k [NO]2 [Cl2]
B) rate = k [NO] [Cl2]
C) rate = k [NO] [Cl2] 2
D) rate = k [NO]
54. The half-life of a reaction is halved when the initial concentration of the reactant is
doubled. The order of the reaction may be ______.
A) zero
B) one
C) three
D) two
Page 11
55. The Mechanism of decomposition of ozone to O2
k2
O + O3 ⎯⎯
→ 2O 2
The Rate Law for the reaction is ______.
A) rate = k [O3][O2]
B)
C)
D) rate = k [O2]2[O3]
56. A proposed mechanism of the reaction 2H2 + 2NO → N2 + H2O is
H2 + 2NO → N2O +H2O (slow)
N2O + H2 → N2 + H2O (fast).
This mechanism predicts that the rate of the reaction is ______.
A) k [H2][NO]2
B) k [H2][NO]
C) k [H2]2[NO]
D) k [H2]2[NO]2
57. A catalyst increases the rate of the reaction by ______.
A) increasing the activation energy
B) decreasing the activation energy
C) decreasing the rate constant
D) increasing the enthalpy of the reaction
58. A catalyst will change the ______ of the reaction.
A) activation energy
B) enthalpy
C) entropy
D) free energy
59. An enzyme catalyzed reaction follows _____.
A) zero order kinetics at low concentration of substrate
B) zero order kinetics at high concentration of substrate
C) first order kinetics at high concentration of substrate
D) second order kinetics at high concentration of substrate
Page 12
60. The rate of a reaction depends on _____.
A) concentration of the reactants
B) temperature of the reactants
C) catalyst used in the reaction
D) all the above
61. The rate constant of a reaction must be stated along with the _____ of the reactants.
A) temperature
B) concentration
C) pressure
D) volume
62. A sphere of volume 10.0 cm3 is converted into eight smaller spheres of each having a
volume of 1.25 cm3. The total surface area of the smaller spheres is _____.
A) 449 cm2
B) 44.9 cm2
C) 63.1 cm2
D) 631 cm2
63. The reaction: 2H2 + 2NO → 2H2O + N2 follows the Rate Law rate = k [H2][NO]2. The
rate of the reaction when [H2] = 0.010 M and [NO] = 0.025 M is 2.4 × 10–6 Ms–1. The
rate constant of the reaction is _____ M–2s–1.
A) 0.38
B) 1.2 × 10–2
C) 7.0
D) 3.2 × 10–4
64. The reaction 2A + 3B → C is a first-order reaction with respect to A and first order with
respect to B. What is the rate constant of the reaction when [A] = 1.60 × 10–2 M and [B]
= 2.40 × 10–3 M and the rate of the reaction is 4.10 × 10–4 M/s_____?
A) 10.7 M–1s–1
B) 1.06 × 10–2 M–1s–1
C) 306 M–1s–1
D) 1.07 × M–1s–1
Page 13
65. The following data were obtained for the acid catalyzed bromination of acetone
[Br2]
[H+]
Rate(M/s)
[CH3COCH3]
0.30 M
0.050 M
0.050 M
5.7 × 10–5
0.30 M
0.10 M
0.050 M
5.7 × 10–5
0.30 M
0.050 M
0.10 M
1.2 × 10–4
0.40 M
0.050 M
0.20 M
3.1 × 10–4
0.40 M
0.050 M
0.050 M
7.6 × 10–5
The Rate Law for the reaction is _____.
A) rate = k [CH3COCH3][Br2][H+]
B) rate = k [CH3COCH3][Br2]
C) rate = k [Br2][H+]
D) rate = k [CH3COCH3][H+]
66. The rate constant for the bromination of acetone according to the data given below is
_________.
[Br2]
[H+]
Rate(M/s)
[CH3COCH3]
0.30 M
0.050 M
0.050 M
5.7 × 10–5
0.30 M
0.10 M
0.050 M
5.7 × 10–5
0.30 M
0.050 M
0.10 M
1.2 × 10–4
0.40 M
0.050 M
0.20 M
3.1 × 10–4
0.40 M
0.050 M
0.050 M
7.6 × 10–5
A) 3.8 × 10–3 M–1s–1
B) 1.8 × 10–5 M–1s–1
C) 2.8 × 10–2 M–1s–1
D) 4.5 × 10–4 M–1s–1
67. The overall order of acid-catalyzed bromination of acetone, according to the data given
below is ________.
[Br2]
[H+]
Rate(M/s)
[CH3COCH3]
0.30 M
0.050 M
0.050 M
5.7 × 10–5
0.30 M
0.10 M
0.050 M
5.7 × 10–5
0.30 M
0.050 M
0.10 M
1.2 × 10–4
0.40 M
0.050 M
0.20 M
3.1 × 10–4
0.40 M
0.050 M
0.050 M
7.6 × 10–5
A) 3
B) 1
C) 2
D) 4
Page 14
68. The decomposition of N2O to N2 and O2 is a first-order reaction with a half-life period
of 3.58 × 103 minutes. If the initial pressure of N2O is 2.10 atm, the total gas pressure of
the mixture after one half-life is ______ atm. (The volume remains constant.)
A) 1.8
B) 2.63
C) 3.07
D) 6.30
69. The units of the rate constant for a third-order reaction is ______.
A) M2s–1
B) Ms–1
C) M–2s–1
D) M–2s–2
70. The rate for the reaction A → B is rate = k. The plot of rate vs. time for the reaction is a
______.
A) curve
B) straight line with a positive slope
C) straight line with a zero slope
D) straight line with a negative slope
71. The plot of concentration of reactant vs. time for a zero order reaction of the type A →
B is ______.
A) Straight line with a positive slope
B) Straight line with a negative slope
C) Straight line with a zero slope
D) Straight line with an infinity slope
72. The half-life of a zero-order reaction is ______.
A) independent of the concentration of the reactant
B) directly proportional to the concentration of the reactant
C) inversely proportional to the concentration of the reactant
D) directly proportional to the square of the concentration of the reactant
Page 15
73. A flask contains both A and B. Both decompose following first-order kinetics with halflives of 50 and 18 minutes, for A and B respectively. If the concentrations of A and B
are initially the same, how long will it take for the concentration of A to be four times
B?
A) 56.4 minutes
B) 28.2 minutes
C) 14.1 minutes
D) 113 minutes
74. The Rate Law for the reaction 2NO2 → N2O4 is rate = k [NO2]2. The value of the rate
constant can be changed by ______.
A) increasing the pressure
B) decreasing the pressure
C) decreasing the temperature
D) decreasing the volume
75. The rate constant can be changed by ______.
A) concentration changes
B) pressure changes
C) addition of catalyst
D) changes in volume
76. The fraction of a radioactive substance remaining after ten half-lives is ______.
Radioactive decay follows first-order kinetics.
A) 10 %
B) 0.01 %
C) 1.0 %
D) 0.1 %
77. A catalyst does not change the ______ of the reaction.
A) mechanism
B) enthalpy
C) energy of activation
D) rate
Page 16
78. The exact Rate Law for the reaction 2H2 + 2NO → 2H2O + N2 is
The Rate Law expression at very high [H2] is ______.
A) rate = k [NO]2
B) rate = k [H2]
C)
D)
79. The Rate Law for the reaction 2H2 + 2NO → 2H2O + N2 is
What is the rate law expression at very low [H2]?
A)
B) rate = k1 [H2]
C) rate = k [NO]2
D) rate = k1 [NO]2[H2]
80. A first-order reaction is 35.5 % complete in 4.90 minutes. The rate constant of the
reaction is ______ min–1.
A) 8.95 × 10–2
B) 1.72 × 10–6
C) 2.30 × 10–4
D) 5.62 × 10–3
81. The plot of ln [A] vs. t of the reaction A → B is a straight line. The order of the reaction
is ______.
A) two
B) zero
C) three
D) one
Page 17
82. The slope of the plot of ln A vs. t of the reaction A → B is – 6.18 × 10–4 min–1. The halflife of the reaction is ______ minutes.
A) 6.12 × 10–2
B) 1.12 × 103
C) 4.15 × 10–3
D) 7.2 × 102
83. The 14C disintegration rates in a fresh and an older piece of wood were found to be 0.26
and 0.186 disintegrations per second per gram of material. The age of the old wood
sample is ______ years. The half-life of 14C = 5.73 × 103 yr.
A) 2.77 × 103
B) 1.97 × 105
C) 277
D) 5.14 × 102
84. The rate law for the reaction: X + 2Y → XY2 is rate = k[X][Y]2. The units of the rate
constant are ______.
A) Ms–1
B) M2s–1
C) M–2s–1
D) s–1
85. For the reaction X + 2Y → XY2, rate = k [X] [Y]2 .When [X] = 0.26 M and [Y] = 0.88
M, rate is 3.8 × 10–3 Ms–1. The rate constant of the reaction is ______ M–2s–1.
A) 2.1 × 10–4
B) 1.9 × 10–2
C) 3.6 × 102
D) 4.7 × 10–6
86. Which of the following have units that depend on reaction order?
A) rate
B) concentration
C) energy of activation
D) rate constant
Page 18
87. The ratio of k1/k2 for the simultaneous reactions of X
and
is 8.0 at 40 °C. What will be the ratio at 300 °C?
Assume the frequency factors of the two reactions are the same.
A) 6.3
B) 7.2
C) 3.1
D) 10.5
88. The reaction A → B → C is called a ______ reaction.
A) consecutive
B) parallel
C) competing
D) stepwise
89. The reaction CO + NO2 → CO2 + NO follows the mechanism
2NO2 → NO3 + NO (slow)
NO3 + CO → CO2 (fast)
The Rate Law for the reaction is ______.
A) rate = k [NO2]2
B) rate = k [NO2][CO]
C) rate = k [CO]2
D) rate = k [NO2]2[CO]
90. The half-life of a first-order reaction is 2.44 × 105 yrs. The time taken for 5.0 × 102 g of
the reactant to decay into 1.0 × 102 g is ______ yrs.
A) 1.2 × 105
B) 4.9 × 106
C) 5.7 × 105
D) 3.9 × 104
91. The rate of the reaction 4PH3(g) → P4(g) + 6H2(g) does not depend on the pressure of
PH3. The rate constant units of the reaction are
A) s–1
B) zero
C) Ms–1
D) M–1s–1
Page 19
92. The reaction Tl+ + 2Ce4+ → Tl3+ + 2Ce3+ follows the mechanism
Ce4+ + Mn2+ → Ce3+ + Mn3+
Ce4+ + Mn3+ → Ce3+ + Mn4+
Tl+ + Mn4+ → Tl3+ + Mn2+
The catalyst in the reaction is ______.
A) Mn2+
B) Mn3+
C) Mn4+
D) Ce3+
93. The reaction Tl+ + 2Ce4+ → Tl3+ + 2Ce3+ follows the mechanism
Ce4+ + Mn2+ → Ce3+ + Mn3+
Ce4+ + Mn3+ → Ce3+ + Mn4+
Tl+ + Mn4+ → Tl3+ + Mn2+
A reaction intermediate in the reaction is ______.
A) Ce3+
B) Mn2+
C) Mn3+
D) Tl3+
94. The first-order rate constant for the reaction (CH3)2O(g) → CH4(g) + H2(g) + CO(g) is
3.2 × 10–4 s–1 at 450°C. Initially only (CH3)2O is present and at a pressure of 0.35 atm.
The pressure of the system at constant volume after 8 minutes is ______ atm.
A) 0.45
B) 5.4
C) 0.54
D) 4.5
95. Water should not be used as fire extinguisher in the titanium industry as it would
catalyze the decomposition of water to ______.
A) H2O2
B) H+ and OH–
C) H2 and O2
D) H2O2 and O3
96. The activation energy for the decomposition of H2O2 is 42 kJ mol–1. When the reaction
is catalyzed by an enzyme its activation energy can become ______ kJ mol–1.
A) zero
B) 7
C) – 84
D) 68
Page 20
Page 21
Answer Key
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
A
C
B
A
C
B
B
A
D
B
A
D
B
C
A
C
B
B
B
B
A
C
B
B
A
D
A
D
A
A
B
B
C
B
A
D
B
A
D
A
C
C
B
A
Page 22
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.
74.
75.
76.
77.
78.
79.
80.
81.
82.
83.
84.
85.
86.
87.
88.
89.
90.
D
B
D
B
D
D
A
C
B
D
C
A
B
A
B
D
A
B
A
A
D
A
C
B
C
C
B
A
A
C
C
D
B
A
D
A
D
B
A
C
B
D
C
A
A
C
Page 23
91.
92.
93.
94.
95.
96.
C
A
C
A
C
B
Page 24