Bodet (ngb299) – Homework 10 – sutcli
ff
e – (51630)
1
This
printout
should
have
20
questions.
Multiplechoice questions may continue on
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before answering.
This is the LAST homework!!
001
10.0 points
NOTE In this question you must consider the
1/a term mentioned in class.
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
[O
2
]
3
·
Δ
t
correct
2.
2
·
Δ
[SO
3
]
Δ
t
3.

4
·
Δ
[S
8
]
Δ
t
4.

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

Δ
[O
2
]
3
·
Δ
t
=
Δ
[SO
3
]
2
·
Δ
t
002
10.0 points
Consider the concentrationtime dependence
graph for two firstorder reactions.
[A]
0
Molar Concentration
of Reactant
Concentration
→
Time
→
Which reaction has the larger rate con
stant?
1.
the reaction represented by the lower
curve
correct
2.
Unable to determine
3.
the reaction represented by the upper
curve
Explanation:
003 (part 1 of 2) 10.0 points
For BOTH the next questions you MUST
consider the 1/a term in the rate equation
for species A, etc.
A ”unique rate” means
’average rate’ taking into account the stoi
chiometric coe
ffi
cients.
In the reaction
3 ClO

(aq)
→
2 Cl

(aq) + ClO

3
(aq)
the rate of reaction of Cl

is 3
.
6
mol
L
·
min
.
What is the rate of reaction of ClO

?
1.
2
.
7
mol
L
·
min
2.
5
.
4
mol
L
·
min
correct
3.
0
.
9
mol
L
·
min
4.
10
.
8
mol
L
·
min
5.
1
.
8
mol
L
·
min
Explanation:
rate of change of [ClO

]
=
3
.
6 mol Cl

L
·
min
3 mol ClO

2 mol Cl

= 5
.
4
mol
L
·
min
004 (part 2 of 2) 10.0 points
What is the unique rate of the reaction?
1.
2
.
7
mol
L
·
min
2.
10
.
8
mol
L
·
min
Bodet (ngb299) – Homework 10 – sutcli
ff
e – (51630)
2
3.
5
.
4
mol
L
·
min
4.
0
.
9
mol
L
·
min
5.
1
.
8
mol
L
·
min
correct
Explanation:
The unique rate is given by
rate of change g species
coe
ffi
cient g species
For this reaction the unique rate is
1
2
×
3
.
6
mol
L
·
min
= 1
.
8
mol
L
·
min
005
10.0 points
If the rate of reaction increases by a factor
of 2.3 when the concentration of reactant in
creases by a factor of 1.5, what is the order of
the reaction with respect to this reactant?
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 Fall '07
 Holcombe
 Chemical reaction, Rate equation, 0.111 M, 0.112 m