CHEMISTRY 1312 SPRING 2018 REVIEW 4
____
1. What is the least penetrating type of radiation?
a. alpha particle
b. beta particle
c. gamma ray
d. both alpha particles and beta particles
____
2. Which of the following reactions is an example of beta particle emission?
a.
b.
c.
d.
____
3. Complete the following fission reaction.
_____ + 3
a.
b.
c.
d.
____4. Alpha particles are identical to
a. helium nuclei.
b. protons.
c. electrons
d. hydrogen atoms.
e. helium atoms.
____5.Indium-122 has a half-life of 10.1 seconds. What is the first-order rate constant for the decay of I-122?
a. 6.86 x 10-2 s-1
b. 9.90 x 10-2 s-1
c. 0.571 s-1
d. 1.62 s-1
____6. As a result of beta decay, the product nucleus is
a. one atomic number higher than the original element
b. two atomic numbers higher than the original element
c. four atomic numbers lower than the original element
d. one atomic number lower than the original element
e. two atomic numbers lower than the original element
____7. When atoms of beryllium-9 are bombarded with alpha particles, neutrons are produced. What new isotope is also
formed?
a.
b.
c.
d.
e.
CHEMISTRY 1312 SPRING 2018 REVIEW 4
____8. What is the missing symbol in this plutonium fission reaction?
a.
b.
c.
d.
e.
____9. The reaction A + 2B → products was found to follow the rate law: rate = k[A]2[B]. Predict by what factor the
rate of reaction will increase when the concentration of A is doubled, the concentration of B is tripled, and the
temperature remains constant.
a. 12
b. 18
c. 5
d. 6
e. 1
____10. The reaction A + 2B → products was found to have the rate law, rate = k[A][B]2. Predict by what factor the rate
of reaction will increase when the concentration of A is doubled and the concentration of B is also doubled.
a. 2
b. 4
c. 6
d. 8
e. 9
____ 11. Which of the statements concerning relative rates of reaction is correct for the decomposition of dinitrogen
pentaoxide?
2 N2O5(g) → 4 NO2(g) + O2(g)
a.
b.
c.
d.
The rate of disappearance of N2O5 is equal to the rate of appearance of NO2.
The rate of appearance of NO2 is equal to the rate of appearance of O2.
The rate of disappearance of N2O5 is twice the rate of appearance of NO2.
The rate of disappearance of N2O5 is twice the rate of appearance of O2.
____ 12. In the reaction below, the rate of formation of O2 is 3.4 x 10-3 mol/L·s. What is the rate of formation of HF?
2 HOF(g) → 2 HF(g) + O2(g)
a.
b.
c.
d.
1.7 x 10-3 mol/L·s
3.4 x 10-3 mol/L·s
6.8 x 10-3 mol/L·s
14 x 10-3 mol/L·s
CHEMISTRY 1312 SPRING 2018 REVIEW 4
____ 13. Which of the following statements are correct?
1. Catalysts are substances that increase the rate of reaction but are not consumed in the reaction.
2. Changes in temperature affect reaction rates.
3. Changes in reactant concentrations affect reaction rates.
a. 1 only
b. 2 only
c. 3 only
d. 1, 2, and 3
____ 14. What is the overall order of the reaction
CO(g) + NO2(g) → CO2(g) + NO(g)
if it proceeds via the following rate expression?
= k[CO][NO2]
a. 1
b. 2
c. 3
d. 4
____ 15. For the reaction 2 NO(g) + Cl2(g) → 2 NOCl(g), the rate law is
= k[NO]2[Cl2].
What are the units of the rate constant where time is measured in seconds?
a. 1/s
b. M/s
c. 1/M·s
d. 1/M2·s
____ 16. For the reaction R → products, which of the following equations corresponds to the integrated expression for
a first-order decomposition reaction?
a.
c.
= kt
= -kt
b.
d. [R]t - [R]0 = -kt
ln
= -kt
____ 17. Which of the following statements concerning collision theory and the Arrhenius equation are correct?
1.
2.
3.
The frequency factor, A, in the Arrhenius equation relates to the number of collisions and the fraction of
those collisions that have the proper geometry for a reaction to occur.
As the temperature increases, the rate of a reaction increases due a greater number of effective collisions.
The activation energy is the energy barrier that must be overcome by reactants for a reaction to occur.
a. 1 only
b. 2 only
c. 3 only
____ 18. Nitrogen monoxide reacts with chlorine to produce NOCl.
2 NO(g) + Cl2(g) → 2 NOCl(g)
A proposed mechanism for this reaction is
NO(g) + NO(g) ↔N2O2(g) (fast, equilibrium)
N2O2(g) + Cl2(g) → 2 NOCl(g) (slow)
What is a rate law that is consistent with this mechanism?
a. rate = k[N2O2][Cl2]
b. rate = k[NO][Cl2]
c. rate = k[NO]2[Cl2]
d. rate = k[NO] 2
d. 1, 2, and 3
CHEMISTRY 1312 SPRING 2018 REVIEW 4
____ 19. The elementary steps for the catalyzed decomposition for dinitrogen monoxide are shown below. Identify the
catalyst.
NO(g) + N2O(g) → N2(g) + NO2(g)
NO2(g) → NO(g) + ½ O2(g)
a. NO
b. N2O
c. N2
d. NO2
____ 20. The elementary steps for the formation of nitrogen and water from nitric oxide and hydrogen are given below.
Identify any intermediates.
2 NO(g) → N2O2(g)
N2O2(g) + H2(g) → N2O(g) + H2O(g)
N2O(g) + H2(g) → N2(g) + H2O(g)
a. N2O2 only
b. N2O only
c. N2O and H2O
d. N2O2 and N2O
____ 21. Which of the following statements correctly describe a chemical system that has reached equilibrium?
1.
2.
3.
a. 1 only
The forward and reverse rates of reaction are equal.
No further macroscopic changes in the system are observed.
The concentrations of reactants and products remain constant.
b. 2 only
c. 3 only
d. 1, 2, and 3
30. Strontium-90 has a half-life of 28.1 years. Starting with 3.20 mg of this isotope, how much would remain after 112.4
years?
31. Iodine-131, t1/2 = 8.0 days, is used in the diagnosis and treatment of thyroid gland diseases. If a laboratory sample of
iodine-131 initially emits 9.95 × 1018 β particles per day, how long will it take for the activity to drop to 6.22
× 1017 β particles per day?
32. Cesium-134 is a β emitter with a half-life of 2.0 years. How much of a 2.50-g sample of cesium-134 will remain after
10 years?
33. Polonium-208 is an alpha emitter with a half-life of 2.90 years. How many milligrams of polonium from an original
sample of 2.00 mg will remain after 8.00 years?
34. Given the initial rate data for the reaction A + B → C, determine the rate expression and k for the reaction.
[A], M
[B], M
Δ[C]/Δt (initial) M/min
0.10
0.20
6.80 x 10-6
0.10
0.40
2.72 x 10-5
0.20
0.40
5.44 x 10-5
35. Given the initial rate data for the reaction A + B → C, determine the rate expression and k for the reaction.
[A], M
0.25
0.25
0.40
[B], M
0.10
0.25
0.10
Δ[C]/Δt (initial) M/s
2.16 x 10-3
5.40 x 10-3
5.53 x 10-3
CHEMISTRY 1312 SPRING 2018 REVIEW 4
36. The compound RX3 decomposes according to the equation
3RX3 → R + R2X3 + 3X2
The following data were collected for the decomposition experiment.
[RX3](mol • L–1)
t(h)
0
0.85
2
0.67
6
0.41
8
0.33
12
0.20
14
0.16
[RX3](mol • L–1)
1
0,8
y = -0.0484x + 0.7755
R² = 0.9499
0,6
0,4
0,2
0
0
5
10
15
Time (hr)
0
y = -0.1197x - 0.1631
R² = 0.9998
ln([RX3])
-0,5
-1
-1,5
-2
0
5
10
15
1/[RX3](M-1)
Time (hr)
7
6
5
4
3
2
1
0
y = 0.3576x + 0.728
R² = 0.9518
0
5
10
15
Time (hr)
a.
b.
c.
d.
What is the order of the reaction?
What is the value of k for the reaction?
Write the differential rate law for this reaction.
Using the correct integrated rate law, predict the concentration of RX3 at 20 hr.
CHEMISTRY 1312 SPRING 2018 REVIEW 4
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
30.
31.
32.
33.
34.
35.
36.
ANS:
ANS:
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ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
A
D
A
A
A
A
E
D
A
D
D
C
E
B
D
B
D
C
A
D
D
0.20 mg
32 days
0.078 g
0.296 mg
Rate = 0.0017 M-2min-1[A]1[B]2
Rate = 0.35 M-2s-1[A]2[B]1
(a) first (b) k= 0.1197 hr-1 (c) rate = 0.1197 hr-1[RX3] (d) 0.077 M