[A] = [A]
0
- kt
t
1/2
= [A]
0
/2k
[A] = [A]
0
e
-kt
ln[A] = ln[A]
0
- kt
t
1/2
= ln2/k
1/[A] = 1/[A]
0
+ kt
t
1/2
= 1/k[A]
0
lnk = lnA - E
a
/RT
ln(k
1
/k
2
) = - (E
a
/R)(1/T
1
- 1/T
2
)
K
p
= K
c
(RT)
D
n
1.
Given:
2NO
2
(g) + F
2
(g)
®
2NO
2
F(g)
rate = -
D
[F
2
]/
D
t
The rate of the reaction can also be expressed as
A.
1/2
D
[NO
2
]/
D
t
B.
D
[NO
2
F]/
D
t
C.
1/2
D
[NO
2
F]/
D
t
D.
-2
D
[NO
2
]/
D
t
E.
-
D
[NO
2
]/
D
t
2.
If the rate of a reaction increases by a factor of 64 when the concentration of a reactant increases by a factor of 4, the order of the reaction with respect to this reactant is
A.
3
B.
4
C.
2
D.
16
E.
1
3.
Consider the following reaction:
2N
2
O(g)
®
2N
2
(g) + O
2
(g)
rate = k[N
2
O]
For an initial concentration of N
2
O of 0.50 M, calculate the concentration of N
2
O remaining after 60 s, if k = 3.4
´
10
-3
s
-1
.
A.
0.41 M
B.
0.63 M
C.
0.31 M
D.
0.50 M
E.
0.82 M
4.
For a first-order reaction, a straight line is obtained from a plot of
A.
[A] vs.
t
B.
ln(
t
) vs. [A]
C.
1/[A] vs.
t
D.
ln[A] vs.
t
E.
ln(1/
t
) vs. [A]
5.
The isotope I-131 has a half-life of 8.05 days. What fraction of the initial concentration of iodine-131 remains after 3 weeks. The decay of I-131 is first-order.
A.
0.164
B.
0.836
C.
0.0861
D.
0.124
E.
0.383
6.
Consider the dimerization of butadiene:
2C
4
H
6
(g)
®
C
8
H
12
(g)
rate = k[C
4
H
6
]
2
If the rate constant is 0.014 M
-1
·s
-1
, calculate the time required for dimerization of 90% of the butadiene for an initial concentration of butadiene of 0.10 M.
A.
79 s
B.
6400 s
C.
6.4 s
D.
160 s
E.
50 s
7.
A certain reaction has a rate constant of 0.0503 s
–1
at 298 K and 6.71 s
–1
at 333 K. What is the activation energy for this reaction? (R = 8.314 x 10
-3
kJ/mol.K)
A.
85.3 kJ/ml
B.
49.9 kJ/mol
C.
34.5 kJ/mol
D.
115 kJ/mol
E.
89.4 kJ/mol
8.
When a catalyst is used in a reaction,
A.
the activation energy of the reverse reaction is increased.
B.
the activation energy for the forward reaction is not changed.
C.
the enthalpy change for the reaction becomes more exothermic.
D.
the forward reaction is increased while the reverse reaction is retarded.
E.
it does not affect the equilibrium concentrations of reactants and products.
9.
Consider the mechanism:
O
3
(g)
b
O
2
(g) + O(g)
fast
O(g) + O
3
(g)
®
2O
2
(g)
slow
An intermediate in this reaction is
A.
O(g)
B.
O
2
(g)
C.
O
3
(g)
D.
O
2
(g) and O(g)
E.
There is no intermediate in this reaction.
10.
The reaction
2NO
2
(g)
®
2NO(g) + O
2
(g)
is postulated to occur via the mechanism below:
NO
2
(g) + NO
2
(g)
®
NO(g) + NO
3
(g)
k
1
, slow
NO
3
(g)
®
NO(g) + O
2
(g)
k
2
, fast
The rate law for this mechanism is
A.
rate =
k
1
[NO
2
]
B.
rate =
k
1
k
2
[NO
3
]
2
C.
rate =
k
1
k
2
[NO
2
]
2
[NO
3
]
D.
rate =
k
1
[NO
2
]
2
E.
rate =
k
2
[NO
3
]
11.
Consider the following reaction:
2HI(g)
b
H
2
(g) + I
2
(g)
If the value of K
c
for this reaction is 0.040 at 1100 K, and initially only 4.00 M HI(g) is present, what is the equilibrium concentration of I
2
(g)?
A.
0.14 M
B.
0.57 M
C.
0.36 M
D.
0.66 M
E.
2.00 M
12.
Consider the reaction
3Fe(s) + 4H
2
O(g)
b
4H
2
(g) + Fe
3
O
4
(s)
If the total pressure is increased suddenly by reducing the volume,
A.
more H
2
(g) is produced.
B.
no change occurs.
C.
more Fe(s) is produced.
D.
more H
2
O(g) is produced.
E.
the equilibrium constant increases.
13.
Consider the following reaction:
3H
2
(g) + N
2
(g)
b
2NH
3
(g)
All of the following will lead to production of more NH
3
(g) except
A.
removal of NH
3
(g).
B.
an increase in pressure by addition of argon.
C.
addition of H
2
(g).
D.
an increase in pressure by addition of N
2
(g).
E.
a decrease in volume of the container.
14.
Consider the following reaction:
NH
4
HS(s)
b
NH
3
(g) + H
2
S(g)
If the value of K
p
for this reaction is 0.11 at 300 K, calculate the equilibrium partial pressure of NH
3
(g) starting from pure NH
4
HS(s).
A.
0.055 atm
B.
0.33 atm
C.
0.22 atm
D.
0.11 atm
E.
0.012 atm
15.
What is the relationship between
K
p
and
K
c
for the reaction below?
2HgO(s)
b
2Hg(l) + O
2
(g)
A.
K
c
= (RT)
2
K
p
B.
K
c
= RT
K
p
C.
K
p
= RT
K
c
D.
K
p
= (RT)
2
K
c
E.
K
p
=
K
c
16.
Given:
2SO
2
(g) + O
2
(g)
b
2SO
3
(g)
At equilibrium at a certain temperature, the concentrations of SO
3
(g), SO
2
(g) and O
2
(g) are 0.12 M, 0.86 M and 0.33 M, respectively. Calculate the value of
K
c
for this reaction.
A.
0.059
B.
0.42
C.
1.31
D.
0.87
E.
0.014
17.
What is the equilibrium constant expression for the reaction below?
CaO(s) + CO
2
(g)
b
CaCO
3
(s)
A.
K
c
= [CaO][CO
2
]/[CaCO
3
]
B.
K
c
= 1/[CO
2
]
C.
K
c
= [CaCO
3
]/[CaO]
D.
K
c
= [CO
2
]
E.
K
c
= [CaCO
3
]/[CaO][CO
2
]
18.
The equilibrium constant for the reaction below
2SO
2
(g) + O
2
(g)
b
2SO
3
(g)
is 11.7 at a certain temperature. What is the equilibrium constant for the reverse reaction at the same temperature?
A.
3.42
B.
0.292
C.
5.85
D.
0.00731
E.
0.0855
19.
The equilibrium constant for the reaction
2SO
2
(g) + O
2
(g)
b
2SO
3
(g)
is 11.7 at 1100 K. A mixture of SO
2
, O
2
and SO
3
, each with a concentration of 0.22 M, was introduced into a container at 1100 K. Which of the following is true?
A.
[SO
3
] = [SO
2
] = [O
2
] at equilibrium.
B.
SO
3
(g) will be formed until equilibrium is reached.
C.
SO
2
(g) and O
2
(g) will be formed until equilibrium is reached.
D.
[SO
3
] = 0.88 M at equilibrium.
E.
[SO
3
] = 0.00 M at equilibrium.
20.
For the reaction
CO(g) + 3H
2
(g)
b
CH
4
(g) + H
2
O(g)
D
H° = -206 kJ. What conditions favor maximum conversion of reactants to products?
A.
low pressure and high temperature
B.
high pressure and high temperature
C.
low pressure and low temperature
D.
removal of H
2
(g) and low temperature
E.
high pressure and low temperature
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