kapur (rk7259) – Suggested Problems 8 – rowland – (53210)
1
This
printout
should
have
27
questions.
Multiplechoice questions may continue on
the next column or page – find all choices
before answering.
001
10.0 points
The rate of formation of NO
2
(g) in the reac
tion
2 N
2
O
5
(g)
→
4 NO
2
(g) + O
2
(g)
is 5
.
78 (mol NO
2
)
/
L
/
s.
What is the rate at
which N
2
O
5
decomposes?
1.
2
.
89 (mol N
2
O
5
)
/
L
/
s
correct
2.
1
.
45 (mol N
2
O
5
)
/
L
/
s
3.
11
.
6 (mol N
2
O
5
)
/
L
/
s
4.
5
.
78 (mol N
2
O
5
)
/
L
/
s
5.
0
.
723 (mol N
2
O
5
)
/
L
/
s
Explanation:
002
10.0 points
Consider the concentrationtime dependence
graph for a firstorder reaction.
[A]
0
Molar Concentration
of Reactant
A
B
C
Concentration
→
Time
→
At which point on the curve is the reaction
fastest?
1.
A +
t
1
/
2
2.
A
correct
3.
C
4.
B
5.
The rates are the same at all points.
Explanation:
Steeper portions of the graph define faster
reactions.
003
10.0 points
Consider the concentrationtime dependence
as shown below for two first order reactions.
[A]
0
Molar Concentration
of Reactant
Concentration
→
Time
→
Which reaction has the greatest t
1
/
2
?
1.
the reaction represented by the lower
curve
2.
the reaction represented by the upper
curve
correct
3.
Unable to determine
Explanation:
004
10.0 points
Consider the reaction below. Which of the
following is a correct expression of the rate?
1
2
S
8
(
s
) + 3 O
2
(
g
)
→
2 SO
3
(
g
)
1.

Δ[SO
3
]
2
·
Δ
t
2.

4
·
Δ[S
8
]
Δ
t
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
kapur (rk7259) – Suggested Problems 8 – rowland – (53210)
2
3.
2
·
Δ[SO
3
]
Δ
t
4.

Δ[O
2
]
3
·
Δ
t
correct
5.
Δ[O
2
]
3
·
Δ
t
Explanation:
rate =

Δ[O
2
]
3
·
Δ
t
=
Δ[SO
3
]
2
·
Δ
t
005
10.0 points
Based on the plot below, what are the units
of the rate constant for this reaction?
[A] (M)
time (min)
1.
s
−
1
2.
M
−
1
·
s
−
1
3.
M
·
min
−
1
correct
4.
M
−
1
·
min
−
1
Explanation:
The yaxis is presented in units of concen
tration. This, together with the fact that the
line has a constant slope, tells us that this is
a zero order process.
The xaxis tells us the
time unit is minutes.
006
10.0 points
Under certain conditions, the reaction
3 A + 4 B
→
5 C
is
observed
to
proceed
at
a
rate
of
0
.
017 M
·
s
−
1
.
What is the corresponding
rate of change in product C?
1.
0
.
00566667 M
·
s
−
1
2.

0
.
085 M
·
s
−
1
3.
0
.
017 M
·
s
−
1
4.
0
.
051 M
·
s
−
1
5.

0
.
017 M
·
s
−
1
6.
0
.
0034 M
·
s
−
1
7.

0
.
00566667 M
·
s
−
1
8.

0
.
051 M
·
s
−
1
9.

0
.
0034 M
·
s
−
1
10.
0
.
085 M
·
s
−
1
correct
Explanation:
The given overall rate is positive which cor
responds to a forward direction as written.
Product C is reacting at 5 times the stated
rate of the overall reaction. C is also a prod
uct, so the concentration is INCREASING
with time, which corresponds to a POSITIVE
rate.
This is the end of the preview.
Sign up
to
access the rest of the document.
 Fall '07
 Madrid
 Reaction, Rate equation

Click to edit the document details