Final Exam
Makeup
Makeup Final Exam
Course:
Instructor:
Proctoring:
Chemistry 100
Armando Herbelin x2882
aherbelin@lcc.ctc.edu
Calculator is OK, No notes.
Time Limit:
2 hours (120 min.)
December 10, 2002
Name:
Calculations:
You must show your work for all calculations. Clearly underline or draw a box around your
final answer which must include the correct number of significant figures and units (if
appropriate).
1
H
1.008
2.1
3
Li
6.941
1.0
11
Na
22.99
0.9
19
K
39.10
0.8
37
Rb
85.47
0.8
55
Cs
132.9
0.7
87
Fr
(223)
*
4
Be
9.012
1.5
12
Mg
24.31
1.2
20
Ca
40.08
1.0
38
Sr
87.62
0.9
56
Ba
137.3
0.9
88
Ra
226.0
Lanthanide
Series
†
Actinide
Series
1
H
1.008
2.1
Atomic Number
2
He
4.003
Symbol
Atomic Mass
Pauling’s
Electronegativity
21
Sc
44.96
22
Ti
47.88
23
V
50.94
24
Cr
52.00
25
Mn
54.94
26
Fe
55.85
27
Co
58.93
28
Ni
58.69
29
Cu
63.55
30
Zn
65.39
39
Y
88.91
40
Zr
91.22
41
Nb
92.91
42
Mo
95.94
43
Tc
(99)
44
Ru
101.1
45
Rh
102.9
46
Pd
106.4
47
Ag
107.9
48
Cd
112.4
57
La
138.9
72
Hf
178.5
73
Ta
180.9
74
W
183.9
75
Re
186.2
76
Os
190.2
77
Ir
192.2
78
Pt
195.1
79
Au
197.0
80
Hg
200.6
89
Ac
227.0
104
Rf
(261)
105
Db
(262)
106
Sg
(263)
107
Bh
(262)
108
Hs
(265)
109
Mt
(268)
58
Ce
140.1
90
Th
232.0
59
Pr
140.9
91
Pa
231.0
60
Nd
144.2
92
U
238.0
61
Pm
(145)
93
Np
237.0
62
Sm
150.4
94
Pu
(244)
63
Eu
152.0
95
Am
(243)
64
Gd
157.3
96
Cm
(247)
65
Tb
158.9
97
Bk
(247)
66
Dy
162.5
98
Cf
(251)
67
Ho
164.9
99
Es
(252)
*
†
5
B
10.81
2.0
13
Al
26.98
1.5
31
Ga
69.72
1.8
49
In
114.8
1.7
81
Tl
204.4
1.8
6
C
12.01
2.5
14
Si
28.09
1.8
32
Ge
72.61
1.8
50
Sn
118.7
1.8
82
Pb
207.2
1.9
7
N
14.01
3.0
15
P
30.97
2.1
33
As
74.92
2.0
51
Sb
121.8
1.9
83
Bi
209.0
1.9
8
O
15.99
3.5
16
S
32.07
2.5
34
Se
78.96
2.4
52
Te
127.6
2.1
84
Po
(209)
2.0
68
Er
167.3
100
Fm
(257)
69
Tm
168.9
101
Md
(258)
70
Yb
173.0
102
No
(259)
71
Lu
175.0
103
Lr
(260)
9
F
19.00
4.0
17
Cl
35.45
3.0
35
Br
79.90
2.8
53
I
126.9
2.5
85
At
(210)
2.2
Information
1 lb = 454 g
1 oz = 28.3 g
C=5/9(F-32)
1 in = 2.54 cm
1 gal = 3.785 L
K=C+273.15
HONClBrIF
G = H-TS
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D==m/V
2.20 lb = 1 kg
n=m/FW
PV=nRT, R=0.0821 Latm/molK
Mass/FWmolesmolesFWmass
C1V1=C2V2
CiVi=CfVf
FW=MW=MM=FM
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C=kPas
PA=xAPA
10
Ne
20.18
18
Ar
39.95
36
Kr
83.80
54
Xe
131.3
86
Rn
(222)
Final Exam
Makeup
1. (20 pts). Molecular Geometry with CH2Cl2.
a. (5 pts.) Draw the Lewis structure of CH2Cl2 (2-dimensional picture).
b. (5 pts.) Copy your picture from (a) and draw dipoles on each bond (you may omit the lone
pairs in this figure). From your picture, is this molecule polar?
c. (5 pts) Draw the 3-Dimensional (tetrahedral) picture of the molecule. The figure on the right
is for your reference – draw you own picture.
Tetrahedron
d. (5 pts) Add dipoles to your 3-D picture (don’t redraw it this time). Is the molecule polar?
Bonus: (5 pts) Briefly explain why the 2-D and 3-D models (pictures) might disagree.
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Final Exam
Makeup
2. (20 pts). Consider the addition of AgNO3 (aq) to a solution of KCl.
a. (5 pts) What will it look like (recall from in-class demonstration)? Include color in your
description.
b. (5 pts) The chemical reaction that occurs is the precipitation of AgCl. Write a chemical
equation that describes the process. Be sure to include the phases for each chemical.
c. (5 pts) What ions are spectators in this process?
d. (5 pts) Write the net ionic equation for the process.
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Final Exam
Makeup
3. (5 pts). In class, we learned how to determine if a molecule is polar. Later, we learned that
polar molecules can stick together by dipole-dipole intermolecular forces. Finally, we learned
that a substance’s boiling point can be related to the strength of intermolecular forces. For each
of these phenomena, write the type of property it relates to.
Phenomenon
Is it Macroscopic or
Microscopic
Is it a Chemical Property
or a Physical Property
Molecule’s Polarity
Dipole-Dipole Force
Boiling Point
4. (15 pts). Early chemists classified the elements by their chemical properties and gave these
groups of elements special names.
a. (5 pts) What feature of the periodic table do these groups correspond to?
b. (3 pts) Write the names of three of these groups.
c. (5 pts) Write the electronic configuration of only one of the following elements (You can
only lose points by doing more!). The element must belong to one of the groups named above.
Write the name of the group that the element corresponds to.
Choices:
Magnesium
Cobalt
Iodine
d. (2 pts) How many electrons are your element’s valence?
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Final Exam
Makeup
5. (3 pts). The alkali metal kalium was discovered in 1807. What is its English name and
symbol?
6. (3 pts). How many hydrogen atoms are in C15H14O5?
compounds.
CH3COOH? Name one of these
7. (4 pts). A cold day in Alaska (according to the fiction of Jack London, not fact) can be 100
below meaning -100F. What is this temperature in Kelvin? Be sure to show your work.
8. (5 pts). Consider the follow graphs of boiling points for chemical classes:
B.P.
Graph A
B.P.
NH3
Graph B
SnH4
SbH3
GeH4
AsH3
SiH4
PH3
CH4
What intermolecular force explains difference in trends between Graph A and Graph B?
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Final Exam
Makeup
9. (15 pts). Lewis Dot Structures
a. (5 pts). Draw the Lewis dot structure and write the chemical formula for carbon
tetrafluoride.
b. (5 pts). Draw the Lewis dot structure and write the formula of sulfur dioxide.
c. (5 pts). Draw the Lewis dot structure and write the formula of the bromate anion.
10. (5 pts). What does HONClBrIF mean?
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Final Exam
Makeup
11. (15 pts). The element bromine (name for the Greek word for stench, brômos) was
discovered in 1826 by Antoine J. Balard.
a. (5 pts). Write its electronic configuration.
b. (5 pts). Fill in electrons for Bromine in the energy level diagram. Label the s, p, and d
orbitals.
E
c. (5 pts). Bromine has two stable isotope with masses 79 and 81. Write the symbol for these
isotopes.
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Final Exam
Makeup
12. (15 pts). Acids.
a. (5 pts) What two factors effect the danger level of acids?
b. (10 pts) If a 100.00 mL of a 1 M solution of hydrochloric acid is diluted to a final volume of
5.000 L, what is the final concentration? Show your work for credit.
13. (10 pts) Electrolytes & Polarity
a. (5 pts) Give an example of an electrolyte. How you can test if a chemical would be an
electrolyte.
b. (5 pts) Draw the structure of water, twice. On one structure, indicate any dipoles that occur
along a bond. On the second structure, indicate the net dipole for this molecule.
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Final Exam
Makeup
14. (30 pts). Consider benzophenone-6, also known as “Uvinul D49” which is added to paints
and plastics to make them resistant to ultraviolet light.
OH O
OH
a. (10 pts) The formula of this compound is C15H14O5. What is its
molecular weight. Recall that the terms molecular weight, molecular
mass, formula weight, and formula mass are essentially the same
thing!
CH3O
OCH3
b. (10 pts) Calculate the percent composition of this molecule. You may show your work above
if you wish (put the answer here!)
c. (10 pts) Write a balanced equation for the combustion of this molecule.
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Final Exam
Makeup
15. (20 pts). Trinitrotoluene is the chemical name for the explosive commonly known as TNT.
Its formula is C7H5N3O6. TNT is manufactured by the reaction of toluene, C7H8, with nitric acid:
C7H8 (l) +
HNO3 (aq) 
C7H5N3O6 (s) +
H2O (l)
a. (5 pts). Balance the equation.
b. (5 pts). If 5.18 lb of toluene is used, how many grams is this?
c. (10 pts). How much nitric acid is needed to react completely with the toluene from (b)?
Report your answer in grams.
BONUS (5 pts). If TNT is burned in air, what percent yield is likely?
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Final Exam
Makeup
16. (10 pts). Consider the salt, KCl.
a. (3 pts) Write a balanced equation for the dissolution of KCl.
b. (2 pts) How many moles of ions are produced for each 1 mole of KCl dissolved?
c. (5 pts) Draw a sketch showing the solvation sphere of each ion. Be sure to orient the water
molecules correctly.
17. (5 pts). Which is stronger, a chemical bond or an intermolecular force?
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