General Chemistry
S2014
C243:
Supplemental
General
Chemistry
Problem
Set
7
(Re:
Chapter
18.6
–
18.11
in
Moore,
et
al.)
Due
May
2,
by
11pm,
online
under
the
Assignments
tab
in
Oncourse.
For
full
credit,
show
all
your
work
or
provide
arguments
for
your
reasoning.
Answers
alone
will
not
be
given
credit
since
I
cannot
tell
if
you
guessed.
18.6:
Gibbs
Free
Energy
1.
A.
Predict
whether
this
reaction
is
product
–
favored
at
25
o
C
by
calculating
the
change
in
standard
Gibbs
free
energy
from
the
data
provided:
H
2
(g)
+
I
2
?
2
HI
(g)
?
H
o
=
53
kJ;
?
S
o
=
166.4
J/K
B.
At
what
temperature
would
this
reaction
shift
from
product
–
favored
to
reactant
–
favored?
2.
Calculate
?
G
f
for
PCl
5
(g)
using
the
following
information:
PCl
3
(g)
+
Cl
2
(g)
?
PCl
5
(g)
?
G
o
=
–
119.3
kJ
18.7:
Gibbs
Free
Energy
and
Equilibrium
Constants
3.
For
each
reaction,
calculate
the
standard
equilibrium
constant
at
298K
and
1000K
from
the
thermodynamic
information
provided
in
Appendix
J.
Indicate
whether
each
reaction
is
product
–
favored
or
reactant
–
favored
at
each
temperature.
A.
2
CO
(g)
+
O
2
(g)
?
2
CO
2
(g)
B.
2
Na
(s)
+
Cl
2
(g)
?
2
NaCl
(s)
4.
For
each
reaction,
calculate
?
G
o
:
A.
2
H
2
(g)
+
O
2
(g)
?
2
H
2
O
(g)
K
c
=
3.3
x
10
81
B.
CH
4
(g)
+
H
2
O
(g)
?
CO
(g)
+
2
H
2
(g)
K
c
=
9.4
x
10
–
1
18.8:
Gibbs
Free
Energy,
Maximum
Work
5.
To
obtain
a
metal
from
its
ore,
the
decomposition
of
the
metal
oxide
to
form
the
metal
and
oxygen
is
often
coupled
with
oxidation
of
coke
(carbon
solid)
to
carbon
monoxide.
For
each
metal
oxide
listed,
write
a
balanced
equation
for
the
decomposition
of
the
oxide
and
for
the
overall
reaction
when
the
decomposition
is
couple
to
oxidation
of
coke
to
carbon
monoxide.
Calculate
the
overall
value
of
?
G
o
for
each
coupled
reaction
at
25
o
C.
Which
of
the
metals
could
be
obtained
from
these
ores
at
25
o
C
by
this
method?
(
Show
your
calculations!!!)
A.
CuO
(s)
B.
HgO
(s)
C.
PbO
(s)
D.
MgO(s)
E.
Which
of
these
metals
could
be
obtained
at
1500
o
C
instead?
18.
1
6.
A
7.
F
1
1:
Therm
o
A
nswer
the
f
A.
At
w
h
B.
If
yo
u
free
e
F
or
the
follo
w
A.
Whi
c
B.
Whi
c
C.
Wha
t
o
dynamic
f
ollowing
q
u
h
ich
point
o
f
u
assume
th
i
e
nergy
upo
n
w
ing
reacti
o
c
h
is
the
kin
e
c
h
product
i
s
t
might
you
and
Kinet
u
estions
for
t
f
the
followi
i
s
diagram
i
s
n
occurring?
o
n
diagram,
e
tic
product
?
s
the
therm
o
do
to
the
re
ic
Stabilit
y
t
he
figures
b
ng
heating
–
c
s
for
water,
p
Briefly
exp
l
a
nswer
the
f
?
Why?
o
dynamic
pr
o
action
to
h
e
y
b
elow.
c
ooling
curv
e
p
redict
whi
c
l
ain
.
f
ollowing
q
u
o
duct?
Wh
y
e
lp
ensure
o
b
e
has
the
hi
g
c
h
phase
ch
a
u
estions:
y
?
b
tain
therm
o
g
hest
entro
p
a
nge
has
th
e
o
dynamic
p
r
p
y?
Briefly
e
e
largest
cha
r
oduct?
e
xplain
.
nge
in
Gibb
s
s