The average rate of disappearance of ozone in the reaction 2O3(g) ® 3O2(g) is found to be 9.0 ´ 10–3 atm over a certain interval of time. What is the rate of appearance of O2 during this interval?
A.
1.3 ´ 10–2 atm/s
B.
9.0 ´ 10–3 atm/s
C.
6.0 ´ 10–3 atm/s
D.
3.0 ´ 10–5 atm/s
E.
2.7 ´ 10–5 atm/s
2.
Consider the reaction X ® Y + Z Which of the following is a possible rate law?
A.
Rate = k[X]
B.
Rate = k[Y]
C.
Rate = k[Y][Z]
D.
Rate = k[X][Y]
E.
Rate = k[Z]
3.
For a reaction in which A and B react to form C, the following initial rate data were obtained:
[A]
[B]
Initial Rate of Formation of C
(mol/L)
(mol/L)
(mol/L × s)
0.2
0.2
0.50
0.4
0.2
2.00
0.8
0.2
8.00
0.2
0.4
1.00
0.2
0.8
2.00
What is the rate law for the reaction?
A.
Rate = k[A][B]
B.
Rate = k[A]2[B]
C.
Rate = k[A][B]2
D.
Rate = k[A]2[B]2
E.
Rate = k[A]3
4.
A general reaction written as 2A + 2B ® C + 2D is studied and yields the following data:
[A]0
[B]0
Initial D[C]/Dt
0.100 M 0.100 M 0.000040 mol/L × s 0.200 M 0.100 M 0.000160 mol/L × s 0.100 M 0.200 M 0.000040 mol/L × s
What is the order of the reaction with respect to B?
A.
1
B.
4
C.
3
D.
2
E.
0
5.
A general reaction written as 2A + 2B ® C + 2D is studied and yields the following data:
[A]0
[B]0
Initial D[C]/Dt
0.100 M 0.100 M 0.000040 mol/L × s 0.200 M 0.100 M 0.000160 mol/L × s 0.100 M 0.200 M 0.000040 mol/L × s
What is the overall order of the reaction?
A.
1
B.
4
C.
3
D.
2
E.
0
6.
A general reaction written as 2A + 2B ® C + 2D is studied and yields the following data:
[A]0
[B]0
Initial D[C]/Dt
0.100 M 0.100 M 0.000040 mol/L × s 0.200 M 0.100 M 0.000160 mol/L × s 0.100 M 0.200 M 0.000040 mol/L × s
What are the proper units for the rate constant for the reaction?
A.
s–1
B.
mol L–1 s–1
C.
L mol–1 s–1
D.
L3 mol–3 s–1
E.
L2 mol–2 s–1
7.
A general reaction written as 2A + 2B ® C + 2D is studied and yields the following data:
[A]0
[B]0
Initial D[C]/Dt
0.100 M 0.100 M 0.000040 mol/L × s 0.200 M 0.100 M 0.000160 mol/L × s 0.100 M 0.200 M 0.000040 mol/L × s
What is the numerical value of the rate constant?
A.
0.000040
B.
0.000160
C.
0.0040
D.
0.0160
E.
4.0 ´ 10–7
8.
A general reaction written as 2A + 2B ® C + 2D is studied and yields the following data:
[A]0
[B]0
Initial D[C]/Dt
0.100 M 0.100 M 0.000040 mol/L × s 0.200 M 0.100 M 0.000160 mol/L × s 0.100 M 0.200 M 0.000040 mol/L × s
For the first of the reactions in the table of data, how many seconds would it take for [A] to decrease to 0.050 M?
A.
1200
B.
1700
C.
170
D.
2500
E.
250
9.
Consider the following data concerning the equation: H2O2 + 3I– + 2H+ ® I3– + 2H2O
[H2O2]
[I–]
[H+]
rate
I.
0.100 M
5.00 × 10–4 M
1.00 × 10–2 M
0.137 M/sec
II.
0.100 M
1.00 × 10–3 M
1.00 × 10–2 M
0.268 M/sec
III.
0.200 M
1.00 × 10–3 M
1.00 × 10–2 M
0.542 M/sec
IV.
0.400 M
1.00 × 10–3 M
2.00 × 10–2 M
1.084 M/sec
The rate law for this reaction is
A.
rate = k[H2O2][I–][H+]
B.
rate = k[H2O2]2[I–]2[H+]2
C.
rate = k[I–][H+]
D.
rate = k[H2O2][H+]
E.
rate = k[H2O2][I–]
10.
Consider the following data concerning the equation: H2O2 + 3I– + 2H+ ® I3– + 2H2O
[H2O2]
[I–]
[H+]
rate
I.
0.100 M
5.00 × 10–4 M
1.00 × 10–2 M
0.137 M/sec
II.
0.100 M
1.00 × 10–3 M
1.00 × 10–2 M
0.268 M/sec
III.
0.200 M
1.00 × 10–3 M
1.00 × 10–2 M
0.542 M/sec
IV.
0.400 M
1.00 × 10–3 M
2.00 × 10–2 M
1.084 M/sec
Two mechanisms are proposed:
I.
H2O2 + I– ® H2O + OI–
OI– + H+ ® HOI
HOI + I– + H+ ® I2 + H2O
I2 + I– ® I3–
II.
H2O2 + I– + H+ ® H2O + HOI
HOI + I– + H+ ® I2 + H2O
I2 + I– ® I3–
Which of the following describes a potentially correct mechanism?
A.
Mechanism I with the first step the rate determining step.
B.
Mechanism I with the second step the rate determining step.
C.
Mechanism II with the first step rate determining.
D.
Mechanism II with the second step rate determining.
E.
None of these could be correct.
11.
A first-order reaction is 35% complete at the end of 55 minutes. What is the value of the rate constant?
A.
1.9 × 10–3 min-1
B.
36 min–1
C.
89 min–1
D.
7.8 × 10–3 min–1
E.
none of these
12.
The following initial rate data were found for the reaction 2MnO4– + 5H2C2O4 + 6H+ ® 2Mn2+ + 10CO2 + 8H2O
[MnO4–]0
[H2C2O4]0
[H+]0
Initial Rate (M/s)
1 ´ 10–3
1 ´ 10–3
1.0
2 ´ 10–4
2 ´ 10–3
1 ´ 10–3
1.0
8 ´ 10–4
2 ´ 10–3
2 ´ 10–3
1.0
1.6 ´ 10–3
2 ´ 10–3
2 ´ 10–3
2.0
1.6 ´ 10–3
What is the value of the rate constant?
A.
2 ´ 105 M × s–1
B.
2 ´ 105 M-2 × s–1
C.
200 M–1 × s–1
D.
200 M–2 × s–1
E.
2 ´ 10–4 M × s–1
13.
The following questions refer to the reaction between nitric oxide and hydrogen 2NO + H2 ® N2O + H2O
Initial Rate of
Initial [NO]
Initial [H2]
Disappearance of NO
Experiment
(mol/L)
(mol/L)
(mol/L × s)
1
6.4 ´ 10–3
2.2 ´ 10–3
2.6 ´ 10–5
2
12.8 ´ 10–3
2.2 ´ 10–3
1.0 ´ 10–4
3
6.4 ´ 10–3
4.5 ´ 10–3
5.1 ´ 10–5
What are the units for the rate constant for this reaction?
A.
L/mol × s
B.
L2/mol2 × s
C.
mol/L × s
D.
s–2
E.
L–2
14.
The reaction H2SeO3(aq) 6I–(aq) + 4H+(aq) ® 2I3–(aq) + 3H2O(l) + Se(s) was studied at 0°C by the method of initial rates:
[H2SeO3]0
[H+]0
[I–]0
Rate (mol/L s)
1.0 ´ 10–4
2.0 ´ 10–2
2.0 ´ 10–2
1.66 ´ 10–7
2.0 ´ 10–4
2.0 ´ 10–2
2.0 ´ 10–2
3.33 ´ 10–7
3.0 ´ 10–4
2.0 ´ 10–2
2.0 ´ 10–2
4.99 ´ 10–7
1.0 ´ 10–4
4.0 ´ 10–2
2.0 ´ 10–2
6.66 ´ 10–7
1.0 ´ 10–4
1.0 ´ 10–2
2.0 ´ 10–2
0.42 ´ 10–7
1.0 ´ 10–4
2.0 ´ 10–2
4.0 ´ 10–2
13.4 ´ 10–7
1.0 ´ 10–4
1.0 ´ 10–2
4.0 ´ 10–2
3.36 ´ 10–7
The rate law is
A.
Rate = k[H2SeO3][H+][I–]
B.
Rate = k[H2SeO3][H+]2[I–]
C.
Rate = k[H2SeO3][H+][I–]2
D.
Rate = k[H2SeO3]2[H+][I–]
E.
Rate = k[H2SeO3][H+]2[I–]3
15.
The following questions refer to the gas-phase decomposition of ethylene chloride. C2H5Cl ® products Experiment shows that the decomposition is first order. The following data show kinetics information for this reaction:
Time (s)
ln [C2H5Cl] (M)
1.0
–1.625
2.0
–1.735
What would the concentration be after 5.0 seconds?
A.
0.13 M
B.
0.08 M
C.
0.02 M
D.
0.19 M
E.
0.12 M
16.
For a reaction: aA ® Products, [A]o = 4.0 M, and the first two half-lives are 34 and 68 minutes, respectively.
Calculate [A] at t= 192 minutes.
A.
0.086 M
B.
0.00 M
C.
0.60 M
D.
1.4 M
E.
none of these
17.
The decomposition of ozone may occur through the two-step mechanism shown:
step 1
O3 ® O2 + O
step 2
O3 + O ® 2O2
The oxygen atom is considered to be a(n)
A.
reactant
B.
product
C.
catalyst
D.
reaction intermediate
E.
activated complex
18.
The following questions refer to the reaction 2A2 + B2 ® 2C. The following mechanism has been proposed:
step 1 (very slow)
A2 + B2 ® R + C
step 2 (slow)
A2 + R ® C
What is the molecularity of step 2?
A.
unimolecular
B.
bimolecular
C.
termolecular
D.
quadmolecular
E.
the molecularity cannot be determined
19.
The following questions refer to the reaction 2A2 + B2 ® 2C. The following mechanism has been proposed:
step 1 (very slow)
A2 + B2 ® R + C
step 2 (slow)
A2 + R ® C
Which step is "rate determining"?
A.
both steps
B.
step 1
C.
step 2
D.
a step that is intermediate to step 1 and step 2
E.
none of these
20.
The following questions refer to the reaction 2A2 + B2 ® 2C. The following mechanism has been proposed:
step 1 (very slow)
A2 + B2 ® R + C
step 2 (slow)
A2 + R ® C
According to collision theory, the activated complex that forms in step 1 should have the following structure. (The dotted lines represent partial bonds)
A.
B.
C.
D.
E.
21.
The following questions refer to the reaction 2A2 + B2 ® 2C. The following mechanism has been proposed:
step 1 (very slow)
A2 + B2 ® R + C
step 2 (slow)
A2 + R ® C
According to the proposed mechanism, what should the overall rate law be?
A.
rate = k[A2]2
B.
rate = k[A2]
C.
rate = k[A2][B2]
D.
rate = k[A2][R]
E.
rate = k[R]2
22.
Two isomers (A and B) of a given compound dimerize as follows: Both processes are known to be second order in reactant, and k1 is known to be 0.25 L/mol × s at 25°C, where In a particular experiment, A and B were placed in separate containers at 25°, where [A]0 = 1.0 ´ 10–2 M and [B]0 = 2.5 ´ 10–2 M. It was found that [A] = 3[B] after the reactions progressed for 3.0 minutes.
Calculate the concentration of A2 after 3.0 minutes.
A.
2.8 ´ 10–22 M
B.
6.9 ´ 10–3 M
C.
3.1 ´ 10–3 M
D.
1.6 ´ 10–3 M
E.
none of these
23.
Two isomers (A and B) of a given compound dimerize as follows: Both processes are known to be second order in reactant, and k1 is known to be 0.25 L/mol × s at 25°C, where In a particular experiment, A and B were placed in separate containers at 25°, where [A]0 = 1.0 ´ 10–2 M and [B]0 = 2.5 ´ 10–2 M. It was found that [A] = 3[B] after the reactions progressed for 3.0 minutes.
Calculate the half-life for the reaction involving A.
A.
4.0 ´ 102 s
B.
1.7 ´ 101 s
C.
2.5 ´ 103
D.
1.8 ´ 102 s
E.
none of these
24.
The decomposition of N2O5(g) to NO2(g) and O2(g) obeys first-order kinetics. Assuming the form of the rate law is where k = 3.4 ´ 10–5 s–1 at 25°C.
What is the initial rate of reaction at 25°C where [N2O5]0 = 5.0 ´ 10–2 M?
A.
3.4 ´ 10–5 mol/L × s
B.
1.7 ´ 10–6 mol/L × s
C.
6.8 ´ 10–4 mol/L × s
D.
5.0 ´ 10–2 mol/L × s
E.
none of these
25.
If the reaction 2HI ® H2 + I2 is second order, which of the following will yield a linear plot?
A.
log [HI] vs time
B.
1/[HI] vs time
C.
[HI] vs time
D.
ln [HI] vs time
26.
Under certain conditions the reaction H2O2 + 3I– + 2H+ ® I3– + 2H2O occurs by the following series of steps:
Step 2.
H3O2+ + I– ® H2O + HOI
(slow, rate constant k2)
Step 3.
HOI + I– ® OH– + I2
(fast, rate constant k3)
Step 4.
OH– + H+ ® H2O
(fast, rate constant k4)
Step 5.
I2 + I– ® I3–
(fast, rate constant k5)
Which of the steps would be called the rate-determining step?
A.
1
B.
2
C.
3
D.
4
E.
5
27.
The reaction 2A + B ® C has the following proposed mechanism: If step 2 is the rate-determining step, then the rate of formation of C should equal:
A.
k[A]
B.
k[A]2[B]
C.
k[A]2[B]2
D.
k[A][B]
E.
k[A][B]2
28.
The questions below refer to the following diagram:
If the reaction were reversible, would the forward or the reverse reaction have a higher activation energy?
A.
The diagram shows no indication of any activation energy.
B.
The forward and reverse activation energies are equal.
C.
The forward activation energy
D.
The reverse activation energy
E.
none of these
29.
The questions below refer to the following diagram:
At what point on the graph is the activated complex present?
A.
point W
B.
point X
C.
point Y
D.
point Z
E.
none of these
30.
What would happen if the kinetic energy of the reactants was not enough to provide the needed activation energy?
A.
The products would be produced at a lower energy state.
B.
The rate of the reaction would tend to increase.
C.
The activated complex would convert into products.
D.
The reactants would re-form.
E.
The products would form at an unstable energy state.
31.
The questions below refer to the following information: The rate constant k for the reaction shown below is 2.6 ´ 10–8 L/mol × s when the reaction proceeds at 300.0 K. The activation energy is 98000 J/mol. (The universal gas constant (R) is 8.314 J/mol × K) 2NOCl ® 2NO + Cl2
Using the following information determine the activation energy for the reaction shown here: 2NO ® N2 + O2
Rate Constant
Temperature (K)
(L/mol × s)
1400
0.143
1500
0.659
A.
3.2 ´ 104 J/mol
B.
9.5 ´ 106 J/mol
C.
2.8 ´ 104 J/mol
D.
6.8 ´ 105 J/mol
E.
2.7 ´ 105 J/mol
32.
The reaction 2H2O2 ® 2H2O + O2 has the following mechanism? H2O2 + I– ® H2O + IO– H2O + IO– ® H2O + O2 + I– The catalyst in the reaction is:
A.
H2O
B.
I–
C.
H2O2
D.
IO–
33.
Which of the following statements best describes the condition(s) needed for a successful formation for a product according to the collision model?
A.
The collision must involve a sufficient amount of energy, provided from the motion of the particles, to overcome the activation energy.
B.
The relative orientation of the particles has little or no effect on the formation of the product.
C.
The relative orientation of the particles has an effect only if the kinetic energy of the particles is below some minimum value.
D.
The relative orientation of the particles must allow for formation of the new bonds in the product.
E.
The energy of the incoming particles must be above a certain minimum value and the relative orientation of the particles must allow for formation of new bonds in the product.
34.
The catalyzed pathway in a reaction mechanism has a __________ activation energy and thus causes a __________ reaction rate.
A.
higher, lower
B.
higher, higher
C.
lower, higher
D.
lower, steady
E.
higher, steady
35.
The rate law for a reaction is found to be Rate = k[A]2[B]. Which of the following mechanisms gives this rate law?
A.
I
B.
II
C.
III
D.
two of these
E.
none of these
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