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Dec
4
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@
100%
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Homework
»
Section
11.3
Questions
1.
Transiate
into
words
all
parts
of
the
following
symbois
@
AN’
CH,
®)
naAM’
CHy
©a
water
2.
Communicate
the
standard
enthalpy
change
by
using
the
four
methods
described
in
this
section
for
each
of
the
following
chemical
reactions.
Assume
standard
conditions
for
the
measurements
of
initial
and
final
states.
(2)
The
formation
of
acetylene
(ethyne,
CH,)
fuel
(AH,®
=
+2274
kW/mol
acetylene)
()
The
simple
decomposition
of
aluminium
oxide
powder
7
=
+1675.7
kl/mol
aluminium
oxide)
(c)
The
complete
combustion
of
pure
carbon
fuel
(AM,"
=
~3935
ki/mol
CO,)
3.
Foreach
of
the
following
balanced
chemical
equations
and
standard
enthalpy
changes.
wrte
the
symbol
and
calculate
the
standard
molar
enthalpy
of
combustion
for
the
substance
that
reacts
with
oxygen.
(@)
2H,(@
+
0,@
-
2H,0@)
AN
=
4838k
(@)
3Fe(s)
+
20,{@)
—
Fe0,(s)
4.
The
neutralization
of
a
strong
acid
and
a
strong
base
is
an
exothermic
process.
H;S0,(aq)
+
2NaOH@q)
—+
Na,SO,(aq)
+
2H,00)
+
14
kJ
(a)
What
s
the
enthaipy
change
for
ths
reaction?
(b)
Write
this
chemical
equation,
using
the
A
4
notation
not
under standard
conditions.
(c)
Calculate
the
molar
enthalpy
of
neutrakization
for
sulfuric
acid.
(d)
Caiculate
the
molar
enthalpy
of
neutralization
for
sodium
hydroxide.
S.
Transiate
the
empirical
molar
enthaipies
given
below
into
a
balanced
chemical
equation,
including
the
standard
enthalpy
change:
for
example,
CH,(@)
+
20,(g)
-
COfg)
+
2H,0(Q)
AH*
=
8025
kJ
(a)
The
standard
molar
enthalpy
of
combustion
for
methanol
1o
produce
water
vapour
is
—725.9
kJ/mol
(b)
The
standard
molar
enthalpy
of
formation
for
liquid
carbon
disulfide
is
89.0
kJ/mol
(c)
The
standard
molar
enthalpy
of
roasting
(combustion)
for
zinc
sulfide
is
—441.3
kl/mol
(d)
The
standard
molar
enthalpy
of
simple
decomposition,
6.
For
each
of
the
following
reactions,
transiate
the
given
standard
molar
enthalpy
into
a
balenced
chemical
using
the
A4
notation,
and
then
rewrite
the
equation
inclucing
the
energy
as
a
term
in
the
equaton
Assume
water
is
produced
as
8
vapour.
()
Propane
obtained
from
natural
gas
is
used
as
a
fuel
in
barbecues
and
vehicies
(Figure
9)
A
=
~20439
ki/mol
CH,
()
Nitrogen
monaxide
forms
at
the
high
temperatures
inside
an
automobile
engine.
AH,."
=
+91.3
kl/mol
NO
(c)
Some
advocates
of
altemative
fuels
have
suggested
that
cars
could
run on
ethanol
AH,"
=
~12348
ki/mol
CHOH
=
gl
Figure
9
Propane-fuelled
vehicles
are
not
allowed
to
park
in
underground
parking
lots.
Propane
is
denser
than
air,
and
8
dangerous
quantity
of
propane
could
accumulate
in
the
event
of
a
leak.
7.
The
standard
molar
enthaipy
of
combustion
for
hydrogen
to
produce
liquid
water
is
—285.8
kJ/mol.
The
standard
molar
enthalpy
of
decomposition
for
liquid
water
is
+2858
kJ/mol
(a)
Write
both
chemical
equations
using
the
A
/"
notation.
(b)
How
does
the
standard
enthalpy
change
for
the
combustion
of
hydrogen
compare
with
the
standard
enthalpy
change
for
the
simple
decomposition
of
bquid
water?
Suggest
a
generalization
1o
include
all
pairs
of
chemical
equations
that
are
the
reverse
of
one
another.
8.
Combustion
reactions
are very
useful
1o
society,
but also
have
some
drawbacks.
Create
a
kst
of
possible
drawbacks
of
our
relilance
on
combustion
reactions,
and
suggest
some
@
o
0
0)
A:dela
(chonge)
b)
n:
o:u
A:dela
hange)
C=
(ombustion
rewction
£:
formalion
reakion
\lscnwp’
H:M
)
B
Twmal
thergy
Choage
of
WA
formakian
of
Zcu\
*
“1(9
el
C;\-\;(,\
formakion
of
etmeme
(CoH,)
(2
Mzey
B)
e
simple
decomposition
2M,03
5
=
YA,
*
302
GY,
foel
frgmn
So\id
Cargen
ond
*
22724
KJ/mol
endothrermic
of
oluminivm
oxide
powder
Y
mowmoes
Wm
>
molar
n&”
Dos
Uw’=
+1675.7
0=
satP
Conditien
™M=
e
©2
SATP
comditiony
hyingu
slwfl
@
20
+
u;(,)
+
22724
Kimel
—
(M,
@
AfHN°m=+2274
Kiimo)
K3
/mo\
AH,".
for
iron(W)
oxide
is
824.2
kJ/mol
possible
solutions.
DemPnhfl
of
A0,
®
endothurmic
YAl
+
3019
Ep
BodWe®:
1676.7
K]
(@
24,05
+
16757
K3
5
YA,
+
30,
Mo
¢)
The
omplele
combuskion
of
pore
carbon
fuel
Cesy
+
O.¢p
—
(O,
[y
(Ombustion
of
carbon
@
Cend
01
cop
°=-393
5k
Bchm’=
-393.510
re——
Exothermic
~I~
©
W
04wy
+
2Na0uwp
=
Nay
S0y
*
2
H0w
*+
MK
Exothermic
feackion
©
C»
*
Oz2cq
=
Oy
+393.5
K1
"ol
B)
WS04
gy
+
2
NaOH
gy
—
Na,
504
gy
*
2
W00
A*H'=
W
W
0)
Ay
H=
W4k
reaction
pathway
¢
molar
eathulpy
for
sobswme
Bk
veads
witn
O
@
o)
ZH,
9+
Oregp
=
2
W0
C)
Dy
Mm
o
W=
Ay
u
d)
By,
B
of
Naok
=
OyMm
n
n
Dy
Mz
~NY
K3
/med
Dyy
U
=zl
K
|
mol
2
ol
DcMR
=
Dch®
DcM®=-4836
W3
Dar
Hon
=
-04
K3ha
soborc
acid
ByWms
=
57
Kol
sodam
yduoide
n
A
clw®
=
-
4336
KT
fmol
@QC
W0
+
-?—
O
—
COrgp*
ZWD
+725.9
K3
2
Deum®
=
-
2908
KT
nydragen
B
Co+
St
CS,
b)
Y4NH
(g
+
70,
p
=
UNOzg
+
6
Walcy
O
1ZnSw
*
302
™
2
Zn0,*
250z.4%
Y413
kI
Deva®
=
-
12720
kifmt
Acn®=
-
12720
d)
2Fe;
03
+
824.2
-
4Fe
+
30,
Y
wmel
Acbm®
=
-313.0K]
oweona
.91
™ol
d)
3FCts)
+
Zouy
-
h‘OQ(S)
@
Ca\"‘(:\
15
°l¢3)
=3
Co;:,\
+
41,000
4
204300
A=
-2043.9
Kijmel
Gy
Ac
H=
Ag“-
(n
D
W=
-
2043.9
kT/mel
(1)
AcH=
-2093.9
k3
C)
2N
4
Oy
+
163.2
K3
=
ZN,0cq
0
ALY
DcH
{I63L_'=.
AW
-y
k3
™l
Adh'=
Dcn®
-
next
p-,f.
n
Achn®
=
Z
W34
K]
/mot
S
-
372.8
KI
ron
Dekm?®
-
M
n
+163.1
Kilmal
2o
Acha®
=
Dcm®=.
gl.6
I
Wlrogen
Agun"
:
