~_'_'f_ ____
Name:_ _ _
8 Dec 2014
Prof. Urban
5C111 Exam, Ch. 9 -11, 24/25, Expt 26G a.
CC-t F1­
Which has the largest lattice energy value? (2 points)
b. Define lattice
1.......
:.ne~gy. ~2!},~if);tS)
~ ~
_
c( ~
... A
ffs
j,<..:h
•
~;A,f)
f7"""'......
,'fW-
~~
11> r,
,~ ~ o~ f
~
tJr..J­
~
.
c. Explain your ansWfr in part a in terms_of the de!~itio~l)of lattice energy. (2 points)
. u..u- i s -ftvt ~+I
•AI\ ~~ ~,,~ -te... ty..
.....
~~
lot;-K
S ...... -I
~.
"7.y a.-Jl...
S-(AJi,.,j
'"t(..,.t
F ;, "....... tlq1 2. Which of the following has the highest electronegativity? (2 points)
5e
a.
5i
Mg
Define electro negativity. (2 points)
#,./:~
fa.....'" .fr.-..
-fo 0. iIr~_d .du {y.... J4..1 i ~
-ft..~ (). ~
~.
3. Provide the Lewis structure for BF3 • (6 points)
••
••
F..
n
.'r--'''!)-''''­
"
\
;F
~
a.
"
Use V5EPR theory to predict the F-B-F bond angles.
b.
What is the hybridization ofthe central atom?
S"p2­
c.
Briefly explain how you determined the hybridization at the central atom.
ts
~
;,
S M.ub:~
bG'Ad.t..Q.. a-~
r
r
r~ ~
Jv $
'I
Sr'L
l (W-
ft; r~
~
~
.::. 4. Provide the Lewis structure for SF4 • (7 points)
:;.'_ 'II
,.
r;:.~ 71<.({:;!:!
,-
:F
3 'f-t.... :f-:
.t
fl
.-.!S-r:.=
t.
\
"F~
f
••
a. What is the VSEPR theory name for the arrangement of the electron groups around the
central atom in SF4 ?..A--v
. I
~
J •
Ill(;)·
_,~
• fO
/-"'''
PI"'6..WI,d~
b. What is the VSEPR theory name for the molecular geometry of SF4 ?
V,1fh"14R -le1r#-~
5.
IT
S -:
t:',
F
W. -S~
Determine the formal charges on all atoms in the Lewis structure below for the N0 3- anion.
(4 points)
-I
t\ o
:O-N=O I
:0:
.. -\
6. Provide the Lewis Structure for NF 3 • (7 points)
••
, (
#
-;: -
....
,.
f·
III
,...."
1'-1 -- f--.... •
I
a. What is the VSEPR theory name for the arrangement of the electron groups around the
central atom in NF3?
b. What is the VSEPR theory name for the molecular geometry of NF3?
c.
Use VSEPR theory to predict the F-N-F bond angles in NF 3.
7. Consider the molecule below: (4 points)
H-C==C-H
:s
a. How many sigma bonds are in the molecule?
b. How many pi bonds are in the molecule?
2­
c. Which orbitals overlap to form the bond between the carbon and hydrogen atoms?
is
M
t\ OJtr-\",\,s
w;~
"Sf'
(fY\
C.
8. Which of the following is true about benzene, C6H6? Circle one. (4 pOints)
a. Benzene contains alternating single and double bonds between adjacent carbon atoms.
@ The pi bonds are formed from six p-orbitals on carbon.
c. There is no pi bonding in benzene.
d. There is no sigma bonding in benzene.
9. Which of the following substances has London dispersion and dipole-dipole forces, but not
hydrogen bond~ces, in the liquid state? Circle all tha~. (4 points)
~
H20
~ (,~cl;::
•~
-l).p1I Jl
•
BF;)
~
t;)1'fC>{A. 'I+~g~
~
• t..~ -1:>:f uIA
10. Which of the following will have the highest boiling point? Which will have the lowest boiling
pOint? Explain your answers. (4 points) 50 2
CO 2 .. .s
r6
r.It~t w.. t
..... 1
-0 ::: C:'='
;::::::
.2'
-III
/'
­
<::)
~
!"> ~Ld.A)e{'f" 81 NIA- fhla..v­
;t f) e,cvdl~
11. Which of the following will have the lowest vapor pressure at room temperature? Which will
have the highest vapor pressure at room temperature? Explain your answers. (4 points)
r
12. Define surface tension. Does surface tension increase or decrease as intermolecular forces
become stronger? Explain your answer. (4 points)
+~ VJ~~fv C-~
J. -r+ I"CfIb..1h- c..n.1t
~ ~. 1 It\-.W~()
tr-r
:J:PlP.
~ tN){e,~
~
[t..
".
~
()/~l~.
~-- r(~~f,~ WI+{ l4.1'f~ty'S
~
I'" ./e-r 0' tv "'" fu.. 1-t.
I/J
JrAA­
13. Which of the following is expected to have the highest viscosity in the liquid state at a given
temperature? Explain your answer. (4 points)
OH
HO
II I > l'(J v S
,..,.0";
oLu-4 fl>,~:>I.(
j
S+r~
tt- \,;,.,.L~
.J­
14. Which level of protein structure is stabilized by backbone hydrogen bonding? (4 points)
a. primary
;
~..
<" (§) secondary
) -<!...
c. tertiary
':l
d. quaternary
<)
~
5
~,..
) -c.-~-7
~ If-.()ol/lldl~
-I'/-f :. 1.33(IIJ/~
111,.0
15. How many kilojoules of heat are required to raise the temperature of 42.0 g of liquid water at
2S.0°C to steam at 112.0°C? (8 points)
~ (,~-
J
For water: Normal melting point O°C Normal boiling pOint 100°C Specific heats:
2.09 Jig C (solid) 4.18 Jig C (liquid)
1.84 Jig C (vapor)
~H fusion = 6.01 kJlmol
~H vaporization = 40.67 kJ/mol
=
0
...
30(12 .Od).'"i. IS- l'",)(wD -2.5"() q 1 ,"",. ~ 1 ' r~ .• fti
VM'1t t 1~' L: ~; J J 0
Q
'i
(D
J3,)t'ttr)/(.), "lb . .,
i ,.
"...
4'J '\:::. 4'f . 8 «<.. J
~l....)
0
l~f-.'o V~F 0
t ' (cf
0
0
l.
'-""
00)( [.f,! 9f-t~1l.D -10/) 'C) , 11.7. 'f~~'1 z..1 AJ
'7IiJ ~ 1;J.a..1"
.? 16. Which of the following will most likely result in a thermoset polymer? (4 points)
e. addition polymerization
f. condensation polymerization @ crosslin king polymerization h. linear polymerization
17. Answer the following questions about the phase diagram shown below. (6 points)
a. Label the normal boiling point on the diagram as
pointA.
b.
P (abn
Label the normal melting point on the diagram as point B. c. Is the solid phase for this substance more or less
dense than the liquid? Explain how you can tell
from the phase diagram.
:rV\e-rt~o r~f;A.L. t~ flf k
10
20
40 50 60 10
T (de;. Celsius)
30
,',..tAL~.
r.I~
4
lANJ-'
Ir Jl,
$I.>/IJ
r
r)
~
18. Complete the addition polymerization reaction below by showing the repeat unit of the polymer
that forms. (3 points)
p.. ~
H
CI
H>====<H
\ ~
I
Addition +f-~-)n
Polymerization
If'
!+
19. Provide the products ofthe reaction below. Provide the name of all functional groups present in
the reactants or products. (7 points)
f(tO"'''' i.<...
"T'
0
\,
L'L
~{/)I' ~01
I ~ '1 OH
I'
~JOH
+
// r1
Reaction jlr'lCOh.b/
ClMho'f.f"Z
~,({
It
G<"-()~
..::.., )
Condensation
eS tA 20. Provide structures for the monomers that could be used to synthesize the polymer Kevlar by
condensation polymerization. (4 points)
1-\ tJ +
?
'l-
I-;;'r fJ f\1... ,-
0
____
..
0
1~-{ }-~-~-o-~~
\
H
H )n
Kevlar
?
Can two Kevlar chains hydrogen bond to each other? Explain your answer. (2 points)
o
o
rJ _C
1
\1 II
',0-1
t-\
1