CHAPTER 8 HOMEWORK
Read Chapter 8 and pp. 415 - 428from Chapter 9.
1. Without using Fig. 8.3, predict the order of increasing electronegativity
groups of elements:
a. Na, K, Rb
r<~ (1<
b. B, 0, Ga
Ga.
c. F, CI, Br
6r
d. S,O,F
S<O<.p
<'
<
in each of the following
<sl«
(!:J
0
c
CJ
<
F
2. Without using Fig. 8.3, predict which bond in each of the following groups will be the most polar:
a. C - H, Si - H, Sn - H
C - 1-\
b. AI - Br, Ga - Br, In - Br, TI - Br
c. C - 0 or Si - 0
C-o
d.O-ForO-CI
O-d
3. Write the complete electron configuration for the most stable ion formed by:
.:J.-
a. S
S
b. Br
6,.-
c. Ra
d. Cs
Cs '1
OVER
CHAPTER 8 HOME\VORK
Read Chapter 8 and pp. 415 - 428/rom Chapter 9.
l . Without using Fig. 8.3, predict the order of increasing electronegativity
groups of elements:
a. Na, K, Rb
R~ (. 1<' <il«
b. B, 0, Ga
c. F, CI, Br
6« 0
(3, ( CJ < F"
d. S,O,F
S<O<P
eDit
in each of the following
«
2. Without using Fig. 8.3, predict which bond in each of the following groups will be the most polar:
a. C - H, Si - H, Sn - H
C-
b. AI - Br, Ga - Br, In - Br, TI - Br
c. C -
°
or Si -
1-\
A~- 6,
° C-o
o -CJ
d.O-ForO-CI
3. Write the complete electron configuration for the most stable ion formed by:
a. S
b. Br
S
.:2-
f•.:2k
r
.",
OX+
c. Ra
r;,;A
d. Cs
Cs -f
OVER
.
-_._----
------
4.
a.
Which of the following ions have noble gas electron configurations?
V' 5+
v", v", Ni2+
.
..~,
~;
.::~'
b. Ta2+, Ta;+, Cd2+
NONf:-
c. Rb2+, Sr2+, Sn2+
d. p3., S3.,
oJ+
Sr
Br·
f
3 -
5. For each of the following groups, place the atoms and/or ions in order of decreasing size:
a. y,
v': v", v"
y
V
)0
c..s
-r
CS+
2· I· C s,+ B a 2+
c. T e",
,,;rt
,.3-4
\j
Rb +
>
>
)
/3o...lot
>
Ie
e. 02-, S2-, S e,2- T e2·
a - ;>
Se .1-
\<
T
.)
"Ie 01 -
:>
pJ-> p ">, p
d. P, p., p2., p3-
s.,.
).-V
~>
>
S
s[o:
>
-t
I
p
.;1- ")
0
C1-
6. Use the following data to estimate the ~Hfo for sodium chloride
Na(s) + ~
Ch (g)
-t
NaCI (s)
-786 kl/rnol
495 kJ/mol
-349 kl/mol
239 kl/mol
109 kl/rnol
Lattice energy
Ionization energy for Na
Electron affinity of CI
Bond energy of CI2
Enthalpy of sublimation for Na
"Jo.
(5)
,'-.l o: of
(~)
t. 1-\
+
.:
)0 t}
u.r
(.i~tAt,~~ 0v~trJ)
e
--a.-
J39
CJ ~)
Cl
Cj)
+
",ItA- 4
(j)
+
e.
d
-7
Cl
~~a' ~
( M~M~l)
- 3VQ )LJ
Cj)
Jo. cJ
_
A<-J
-
(s)
(I./lr-trnc,( ~A~rJ)
(MVJ)\
(~
OJJf1J)
~~rI)
c.
7. Use bond energy values to estimate ~H for each of the following reactions:
';;,~~}itffi·
TABLE 8.4
Avera~e Bond Ener~les (kj/mol)
Single Bonds
H-H
H-F
H-Cl
H-Br
H~I
N-H
N~N
N'"-F
N-Cl
N-Br
N-o'
O-H
0-0
432
565
427
363
295
C-H
C-C
C-N
C-O
C-F
C-Cl
C-Br,
C":""l' 'C":""S
413
347
305
358,
485
339"
276
240"'"
259
O..:....P
o-cr'
0-1
F-F
F'-Cf"
F-Br
CI-CI
Cl-.-Bh
Bt-Bt,
Multiple Bonds
I-I
I-Cl
I-Br
149
208
175
S-H
S-F
S-Cl
S'-Br
S-S
347
327
253
218
266,
Si-Si
Si-H
Si-C
154
253"" , Si~',
340
393'
360
452
391
160'
272
200
243
201
467
146
190
203;
234
C=C
C=C
0=0
C=O*
C=O
N=O
N=N
NEN'
C N
C=N
614;
839
495ii
745,,]
1072 ~
607J::.!
418
941':
891{
61S~
.~
:~
237
239
218
193','
1
~
.~
!~
I
*C=O(C02)
a. HCN (g) + 2 H2 (g) - CH3NH2 (g)
H-
c,:::~
+ ~ H-i-\
-'?
,
(-----'-··~-~--_=--i
~KJ~
.i
.-
~
H-t-"i
I
- I;; O.
H-
,1./
I
OVER
= 799
8. Write Lewis structures that obey the octet rule for each of the following:
a. HCN
1-1
=(1)1
C
z:
N
I
.:
(I)
t..-J
L-f ~
S::
.s
-
/0
z: (,)
~.
"ALe
eo,.!Q
----e.-
:' .~
~
b. NH4+
N "
(I).s .:
l-i.:-
(4) I
~_(_'
S
1-1
s:
-_1 _
+_) __
,tAL
8
e:
c. H2CO
Ii -=
(z) 1-=
..
J.
:-'-1
C=(I)'-l
••
H
~
vALe-::
I;:),
60NDe-.::
~
~
~'"-I
9. Write Lewis structures that obey the octet rule for each of the following molecules and ions (in each
case the first atom listed is the central atom).
•
a. POCh
p=
.
.5
(I)~=
o .:(I) ~:; ~
ex!: (J) ~J_
0AL t
80,JD
3~
:
e
z:
----~
g
.
I
,
.' CJ. - P ,
.r
.»,
t''-..{4
,
C1. :
..
.
,
!F :
C.
SF4
S
s:
1="--
(I
I.,
(,)
. .,
,e
, I
...
-
" ..
7 .: J.R
(Y)
S·-c-.
"
,
e - .: 3 L/
'fA L
e- -
(j()rJO
.
; F,'
'6
----
~~
••
..
•· F ••
/
d. CIFs
I
1
a:(I)1;:
,
Cf
:F
F .: (s) 1 .: 3..s
e-.:
/-
I
v A Le-:-----;--1d..-Bot-J\)
...
.. •,
I
o.
•0
/
••
'-...
• I•
I
t
HI
/0
3d
e. SF6
S--
'"
(I) ~ ~
t- .: (I.) 1 -- l./J.
-vA,l
e. -
aO",,))
e:
, v
f
S
/'
,
/.
<,
tI
...-,
• l•
.~,
f-
I
/J.
--
.',c~,
I
<,
:t::
1{8
.:
.
:1=""
,,
~
..
: r- ~
"
":
.
~"
I
4
•
I
- 3("
II. Write Lewis structures for the following. Show all reso.nance structures w~~re applicable:
\\.. :?:}-"J
a. N03"
.s
r-.1=(I)S-=
0-; (3) ~
cJ~'1t{I-)
VALe.
- Ii'
b. OCN"
O=(I)~::
tJ :
L\
'Il~l.
e ,-
s:
e-
.:
,I"
y
z:
.s
r
(3o"lb
~ 8
(.I)
(I) S -:
C~D../'~.f
(1-)
"
z: '"
to·.
~tl
-
(,)
<-/
L' .
::- ~
BV",D e -
C=
\:O-J-~
I~
~
,,0 "'~" .'J1:
(
)
(tJ
:...f.), ~
r~M
~
._-
-----
-------
-
0:
>
-.
•• :O~
II
.,
;O-,J-O:
."
...•
J-'-
~,
;
sol
b.
s
s:
\
Jlt
{)" (y)~:
e-
I~UrJQ
e-
c. NF3
(/).$'=
a
eOtJL>
s:
i
J
I
J
.
'0'
'
: F - ;j- \:.:
----
~•
I
t
'F '
,;) (p
'fA\.e,.-
!
.-
to
\'--
S
7 .: ;;
._---
. .0,
"
S - 0
-
').-
8
,'-1::
(3)
3
z:
0',
\
\
(<1-) _---~-~
V,iL.
F::
\
(Il ~.: ~
cJ"\Il.'j-t
..
\
!
!
"
e
I
I
~
»»
10. Write Lewis structures for the following molecules or ions, which have central atoms that do not
obey the octet rule:
••
.•
·c
a. PFs
2>
f::(I)~:
F
s:
(s)
7
z
• I
.. •
3.s
\
<,
\-
. ,-
•
,
•.
I
rr:
------:{AL e-;~O
j3u~De-~
-----
.. F •. ..
,- '.
p ~ .-.'
30
b. BeH2
d
0e.:(I)J----
1+.::-
Cd) I
-
If - l3e - 1-1
d.
-.fAle.- :
.1../
0drJ!)Q-:
A./
OVER
12. Consider the following bond lengths:
The carbon - oxygen single bond = 143 pm
The carbon - oxygen double bond = 123 pm
The carbon - oxygen triple bond = 109 pm
.,
a. POCh
P
.'0 ,'
..,
.c»-
,
•.•
I
1
Fe:::
5-
*
(8')
s:
+
I
~•
P - cJ:
,
•
II
:Cl:
••
C~
i-C=
7-~(~)=:
OVER
+3
x~
c. Xe04
.
. .
.0'
,
..
Fe:; ~ - ~ (g):
I
4(
+
'Ie. - 0:
~O
,.
•
-0
•
.-
•
.
.
.
"
d. CI03'
., .... lj.'O"-C~-O~
••
I
-
cl
F'C - 7- ~ - {(ra)'::
+J.
.
:O·
••
IS. Write Lewis structures, then predict the molecular structure, bond angles, and polarity of each of the
following molecules or ions:
..o·.
Tl'~\(00 klA L
A Ll
·
,·0.
0',
• •
,/
b. Nl,
.. o. ..
..F - tJ- f.~
.
IIY.I. L
loq. S-O
POlAiZ
••
•
.
(.
: F - T-•~
p')RAM
AR..E
A.-j(!;.LE S
. ,t
r- •
",
I)
"ION POLA;t
Tr2.1 G,ot-..IAI..
I
I
I ;).0
~.-J Ci>LES
•
• •
..
PLA...JA"-
I
.1-.
• r- •
t •
i- :
~
.
.T -
.0
k.o./O~
A"'~L~5
f-\~6Ll?5
ItNO
d.
Aft~
AIt~
0
12.0
qoo
rJo.J n-l~
HoR-I~O,JIA'-..
'3ETWt.;l::;tJ 1l+~ VRTIU\L
110fl./ t:Of-l'rr::jL
Pl4NE..J
t •
POtAj~
---- -_. ----------
---_._._------
----_._----_.
~'
;c ~
'j
\
-,
. c·
~,
'Il
..
.. •
r. .
..
-.
,F •
•
·
e. AsFs
••
,F
•«
v
\
- As
»: ,
<,
\
I-
.
,.
,
,• c·
t
LI r-J £'Ale
0=(=0
,{1,jXt..
OAf1
Ai 1M. f Jl,j,t.,\
••
g. SeF6
••
•c •
3
•.
8
..
I
:1=
..
•
•r,
•r 0
••
OVER
..
~ CJ ~
\
17. Use the localized electron model to describe the bonding in CCI4
CC~~ Lo .:k.t~j'f.J,t.J}lYU}-(,(.,rtd ffi CA,v~ ti10»t.
:
ALr,~
1M I~.~\
:Sf
h"J nt-:4. ~~
/VV\~Ct
dw .::t
Cl
-3
-,~IJ-{M
cs
c(,tcmA, ~\
C1
. v/IL Jto«A .~f I. •~
~~J~
3
;t;t~
C-1
a' h1d,o
dUll'- .:
C ~
/' \
(J .-
:~ ~ ·~
.,w-u( ....-i:b..
-L o ~f3 1J~.u1
u-t
~~.t-v~vf
••
.3i~ ~
.
~.A
•
19. For each of the following molecules or ions, write the Lewis structure(s), predict the molecular
structure (including bond angles), give the expected hybrid orbitals on each central atom, and predict the
overall polarity:
P'll!.4W1
nlGOM4L
AM-GLES
3
.. /tJ,
: 1-
lOt{.
oS
0
Sf
~':
..
I
alE
fDAL
PoUtfl...
.
••,F ••
o •
,
, r:"
•
SIZ k: - SAw
.
110t.llo,J-rAL
~F
I/8l..TI<AL
~.'" I-e.
I
:f /
I
• f-
o
I
'I,
I
12...0
PLA"'€
l'./O
/ Hotl.1 Co AJTJ.IL
o
3
sp d
~
•
POLA~
. ..
P
""
c. PCls
,
.
(21
~I
r'
: CJ :
(
-
f
---
"
• C ~.
(
I
•
I. t
.,
C-f "
••
I.
f
C-R,'
••
(31 P'IiM. M \ 1)1.\L
T!'( I G.otJAL
PI...AtoJ E:
I-}ORIco!JTAL
vEllTIU\L
3
/
HO~I1;OlViA\.
sf d
NO,JPoLA
L
I~O •
PLAiJf
qo 0
..
....
/
d. IF5
-..
..
•.1"r- ••
:
--
t
: F--.....
I
<,
••
'
~QvAX...E
.
! ,
Sf
••
F.'
J ......
<10°
(lr-..l6LES
,-,
I~'
P'f(i!.AM ID
'3ri~
POLAR...
,~
e. S03
90'
. ~
tI
.
/
'
S
.0.
f
PLA~AIt
A~ 6LES
.;l.
<100
Sp
.
'- ,0,' .
,J 0 N PuL AR.
•
•
.
r
(
TETTZAHE.uiU\l
·0·
t
•
AtJGLES
I
\
J'Q\(,oNAL
.,
• r
,/'
S --....
I
I ' .:>
l"
't
_,0••
S{l
3
POU),lt
..
: 0:
OVER
I
oq.
S
o
20. Biacetyl and acetoin are added to margarine to make it taste more like butter.
Biacetyl:
; O~;O:
11- II
CH3
C - C - CH3
-:-
Acetoin:
;0 :
II
CH3
CH - C - CH3
-
I
••
:OH
Complete the Lewis structures, predict values for all the C-C-O bond angles, and give the hybridization of
the carbon atoms in these two compounds. Are the four carbons and two oxygens in biacetyl in the same
plane? How many (J bonds and how many 1t bonds are there in biacetyl and acetoin?
131().tE T'f L
f~ 1Q
C- C - 0
s
ft~ J fMAjllQ au
c i: :- sf
c ~ 5(>
e ~ . .sf'
. 3
sf
t.f
C
Jiv.
a,.,.J. ~j f"''\..O
~
cr:
\\
11 ~
d
f112ETOIl\J
3
C I
10?
$()
3
C J
!?
'J
C
Sf)
:3 • Sf
,
t(
Cf ::
11
-
Sf
13
'l.
3
s "
loif.SO
/';;'0
lot;.S
0
CIA.!
,.ttJ--7 ~.. ~
~
/~..L.