White Station High School
Name______________________________________
Chapter 13 ʺKineticsʺ Section: A1, A2, A3
TRUE/FALSE. Write ʹTʹ if the statement is true and ʹFʹ if the statement is false.
1) The instantaneous rate of a reaction can be determined from the graph of molarity versus time at any
point on the graph.
T or F
2) The concentration of reactants or products at any time during the reaction can be calculated from the
integrated rate law.
T or F
3) The half life for a first order rate law depends on the starting concentration.
T or F
4) Heterogeneous catalysts have different phases from reactants.
T or F
5) Rates of reaction can be positive or negative.
T or F
6) The rate limiting step in a reaction is the slowest step in the reaction sequence.
T or F
7) The overall reaction order is the sum of the orders of each reactant in the rate law.
T or F
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
8) __________ are used in automotive catalytic converters.
8)
A) Enzymes
B) Nonmetal oxides
C) Noble gases
D) Homogeneous catalysts
E) Heterogeneous catalysts
9) The rate law of the overall reaction
9)
A + B → C
is rate = k[A]2 . Which of the following will not increase the rate of the reaction?
A) increasing the temperature of the reaction
B) increasing the concentration of reactant A
C) increasing the concentration of reactant B
D) adding a catalyst for the reaction
E) All of these will increase the rate.
A‐1
10)
10) A catalyst can increase the rate of a reaction __________.
A) by providing an alternative pathway with a lower activation energy
B) by lowering the overall activation energy (Ea ) of the reaction
C) by changing the value of the frequency factor (A)
D) by lowering the activation energy of the reverse reaction
E) All of these are ways that a catalyst might act to increase the rate of reaction.
11) Of the following, __________ will lower the activation energy for a reaction.
11)
A) raising the temperature of the reaction
B) adding a catalyst for the reaction
C) increasing the concentrations of reactants
D) removing products as the reaction proceeds
E) increasing the pressure
12) Which energy difference in the energy profile below corresponds to the activation energy for the
forward reaction?
A) x
B) y
C) x - y
D) x + y
13) The primary source of the specificity of enzymes is __________.
12)
E) y - x
13)
A) their locations within the cell
B) their bonded transition metal, which is specific to the target substrate
C) their delocalized electron cloud
D) their shape, which relates to the lock-and-key model
E) their polarity, which matches that of their specific substrate
14) In general, as temperature goes up, reaction rate __________.
A) goes up if the reaction is endothermic
B) stays the same if the reaction is first order
C) stays the same regardless of whether the reaction is exothermic or endothermic
D) goes up if the reaction is exothermic
E) goes up regardless of whether the reaction is exothermic or endothermic
A‐2
14)
15) Which one of the following is not a valid expression for the rate of the reaction below?
15)
4NH3 + 7O2 → 4NO2 + 6H2 O
A)
1 Δ[H2 O]
6
Δt
1 Δ[O2 ]
B) - 7
Δt
1 Δ[NH3 ]
C) - 4
Δt
D)
1 Δ[NO2 ]
4
Δt
E) All of the above are valid expressions of the reaction rate.
16) The rate of a reaction depends on __________.
16)
A) collision energy
B) collision orientation
C) collision frequency
D) all of the above
E) none of the above
17) The half-life of a first-order reaction __________.
17)
A) does not depend on the initial reactant concentration
B) is constant
C) is the time necessary for the reactant concentration to drop to half its original value
D) can be calculated from the reaction rate constant
E) All of the above are correct.
18) One difference between first- and second-order reactions is that __________.
A) the rate of a first-order reaction does not depend on reactant concentrations; the rate of a
second-order reaction does depend on reactant concentrations
B) the rate of a first-order reaction depends on reactant concentrations; the rate of a
second-order reaction does not depend on reactant concentrations
C) the half-life of a first-order reaction does not depend on [A]0 ; the half-life of a second-order
reaction does depend on [A]0
D) a first-order reaction can be catalyzed; a second-order reaction cannot be catalyzed
E) the half-life of a first-order reaction depends on [A]0 ; the half-life of a second-order
reaction does not depend on [A]0
A‐3
18)
19) The elementary reaction
19)
2NO 2 (g) → 2NO (g) + O2 (g)
is second order in NO2 and the rate constant at 501 K is 7.93 × 10-3 M-1 s-1 . The reaction half-life
at this temperature when [NO2 ]0 = 0.450 M is __________ s.
A) 126
B) 280
C) 87
D) 0.011
E) 3.6 × 10-3
20) The combustion of ethylene proceeds by the reaction
20)
C2 H4 (g) + 3O2 (g) → 2CO2 (g) + 2H2 O (g)
When the rate of disappearance of O2 is 0.23 M s-1 , the rate of disappearance of C2 H4 is
__________ M s-1 .
A) 0.35
B) 0.69
C) 0.15
D) 0.077
E) 0.46
21) At elevated temperatures, nitrogen dioxide decomposes to nitrogen oxide and oxygen:
1
NO2 (g) → NO (g) + O2 (g)
2
21)
The reaction is second order in NO2 with a rate constant of 0.543 M -1 s-1 at 300°C. If the initial
[NO2 ] is 0.260 M, it will take __________ s for the concentration to drop to 0.100 M.
A) 0.299
B) 8.8 × 10-2
C) 3.34
D) -0.611
E) 11.3
22) The reaction
22)
2NO2 → 2NO + O2
follows second-order kinetics. At 300°C, [NO2 ] drops from 0.0100- to 0.00650-M in 100 s. The rate
constant for the reaction is __________M-1 s-1 .
A) 0.54
B) 0.096
C) 0.65
A‐4
D) 1.2
E) 0.81
23) At elevated temperatures, methylisonitrile (CH3 NC) isomerizes to acetonitrile (CH3 CN):
23)
CH3 NC (g) → CH 3 CN (g)
The dependence of the rate constant on temperature is studied and the graph below is prepared
from the results. The energy of activation of this reaction is __________ kJ/mol.
A) 1.9 × 104
B) 4.4 × 10-7
C) 4.4 × 10-4
D) 1.6 × 105
E) 160
24) The rate constant of a first-order process that has a half-life of 225 s is __________ s-1 .
24)
A) 4.44 × 10-3
B) 12.5
C) 3.08 × 10-3
D) 0.693
E) 1.25
25) The decomposition of N 2 O5 in solution in carbon tetrachloride proceeds via the reaction
2N2 O5 (soln) → 4NO2 (soln) + O2 (soln)
The reaction is first order and has a rate constant of 4.82 × 10-3 s-1 at 64°C. The rate law for the
reaction is rate = __________.
[NO2 ]4 [O2 ]
A) k
[N2 O5 ]2
B) 2k[N2 O5 ]
C) k[N2 O5 ]
D) k
[N2 O5 ]2
[NO2 ]4 [O2 ]
E) k[N2 O5 ]2
A‐5
25)
26)
26) The rate of disappearance of HBr in the gas phase reaction
2HBr (g) → H2 (g) + Br2 (g)
is 0.190 M s-1 at 150°C. The rate of reaction is __________ M s-1 .
A) 0.086
B) 2.63
C) 0.095
D) 0.0361
E) 0.380
27) The decomposition of N2 O5 in solution in carbon tetrachloride proceeds via the reaction
27)
2N2 O5 (soln) → 4NO 2 (soln) + O2 (soln)
The reaction is first order and has a rate constant of 4.82 × 10-3 s-1 at 64°C. If the reaction is
initiated with 0.058 mol in a 1.00-L vessel, how many moles remain after 151 s?
A) 0.055
B) 2.0 × 103
C) 0.028
D) 12
E) 0.060
28) Which one of the following graphs shows the correct relationship between concentration and time
for a reaction that is second order in [A]?
A)
B)
C)
D)
E)
A‐6
28)
29) In the Arrhenius equation,
29)
k = Ae-Ea/RT
__________ is the frequency factor.
A) A
B) k
C) e
D) R
E) Ea
30)
30) The isomerization of methylisonitrile to acetonitrile
CH3 NC (g) → CH3 CN (g)
is first order in CH3 NC. The rate constant for the reaction is 9.45 × 10-5 s-1 at 478 K. The half-life
of the reaction when the initial [CH3 NC] is 0.030 M is __________ s.
A) 5.29 × 103
B) 3.53E × 105
C) 1.06 × 104
D) 1.36 × 10-4
E) 7.33 × 103
31) A particular first-order reaction has a rate constant of 1.35 × 102 s-1 at 25°C. What is the
magnitude of k at 95°C if Ea = 55.5 kJ/mol?
31)
A) 2.85 × 104
B) 1.36 × 102
C) 576
D) 4.33 × 1087
E) 9.60 × 103
The data in the table below were obtained for the reaction:
2 ClO2 (aq) + 2 OH- (aq) → ClO3 - (aq) + ClO2 - (aq) + H2 O (1)
Experiment
Initial Rate
Number [ClO2 ] (M) [OH ] (M)
(M/s)
1
0.060
0.030
0.0248
2
0.020
0.030
0.00276
3
0.020
0.090
0.00828
32) What is the order of the reaction with respect to ClO2 ?
A) 3
B) 2
C) 0
32)
D) 1
A‐7
E) 4
The data in the table below were obtained for the reaction:
A + B → P
Experiment
Initial Rate
Number [A] (M) [B] (M)
(M/s)
1
0.273
0.763
2.83
2
0.273 1.526
2.83
3
0.819 0.763
25.47
33) The magnitude of the rate constant is __________.
A) 2.21
B) 0.278
33)
C) 38.0
D) 42.0
E) 13.2
The reaction A → B is first order in [A]. Consider the following data.
time (s) [A] (M)
0.0
1.60
10.0
0.40
20.0
0.10
34) The half-life of this reaction is __________ s.
A) 4.9
B) 3.0
34)
C) 7.1
D) 0.14
A‐8
E) 0.97
Answer Key
Testname: EXAMKINETCSCHP13CHANG
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FALSE
TRUE
FALSE
TRUE
FALSE
TRUE
TRUE
E
C
A
B
A
D
E
E
D
E
C
B
D
E
A
E
C
C
C
C
B
A
E
E
B
C
A
A‐9