Prof. Thomas Greenbowe
Dr. Jesudoss Kingston
CHEM 177
Hour Exam I
September 12, 2011
This exam consists of 2 parts
on 9 pages
Parts
Grading
Points
Page 3
18 pts
Page 4
18 pts
Page 5
12 pts
Page 6
18 pts
Page 7
16 pts
Score
sheets only
________
________
________
20 pts
TOTAL
102 pts
Recitation TA_______________
Recitation Section____________
on scantron
Page 8
Name______________________
________
TA Name
Abekoon
Anderson
Berry
Carlson
Chatterjee
Durfey
Everett
Fritzsching
Gupta
Hutchinson
Johnson
Khan
Klobukowski
Kumar, N.
Kumar, S.
Kwolek
Lampland
Maligal Ganesh
Marchuk
Pindwal
Reinig
Stender
Tomlinson
Van Zeeland
Walen
Wanninayake
Weinstein
Wiley
Zenner
Sections
21,57
11,30,46
39,62
55
29,42
26,63
8,60
47,54
25,33
6,48
40
37,43
12,44
20,28
1,2
5,9
38,41
13,18
45
31,59
15,56
19
7,10
36,52
3,22
4,64
53,58
24
23,27
Time
10, 12
2, 5, 3
11, 8
10
4, 1
3, 9
1, 5
4. 5
2, 9
11, 5
12
10, 1
3, 2
9, 4
8, 9
11, 1
11, 12
3, 5
2
8, 2
4, 11
8
12, 2
10, 3
10, 11
10, 12
4, 1
1
12, 3
NOTE: To receive full credit on problems, you must clearly show all work and your method of determining
the answer must be clear. The final answer must be reported to the correct number of significant figures and
have the correct units. Questions are written on both sides of each page. The last page contains useful
information and a periodic table; the last page should be removed and used for scratch paper and as a reference.
Do not put answers on the tear away page.
The last day to drop Chem 177 and add Chem 50 as a full semester is Wednesday, September
21, at 5 pm. See your academic adviser to obtain the Drop/Add form and bring it to the
General Chemistry Office, Room 1608 Gilman Hall.
2
Please read the following instructions carefully before proceeding! Part I of your exam will be computer
graded. In order for the computer to identify who you are, it is important that you complete the information
section properly.
You must use a #2 pencil and completely fill in the appropriate circles on the BLUE computer scan sheet.
1.
To help you code the correct circles, first
write your last name, first name and
middle initial in the boxes (skip a space
between each). Then darken the circles
that match the letters in the box above it.
See the sample to the right.
2.
Write the middle nine digits of your ISU
identification number in the boxes A-I.
Do not skip any spaces. Below each
number, darken the circle that matches
this number. For example, 123456789.
See the sample at bottom right.
3.
Write your recitation section number in
the special code area, boxes K-L. Do not
skip any spaces. For example, if you are
in section 8 of Chem 177, write 08.
Again, darken the circle that matches the
number above it. See the sample at
bottom far right.
In Part I, select the one best answer for each
question. Place your answer on the computer
answer sheet by darkening the proper circle for
that question. Your computer scan sheet will
be your official answer sheet for Part I.
All material (exam, answer sheet, scratch
paper) must be returned to your TA in order for
us to grade your exam.
Exam #1: Chem 177, Fall 2011
3
Part I: Multiple Choice: (3 pts each). The answer you fill in on your bubble sheet is the one that will count. You
should circle the answer on this sheet for your own reference.
1. Mass of an empty container
Mass of the container plus a rectangular metal piece
Dimension of the rectangular metal piece
3.0 grams
25.0 grams
3.00 cm × 6.00 cm × 0.50 cm
The data above were gathered in order to determine the density of the unknown metal piece. The density of
this metal piece should be reported as
a) 0.5 g/cm3
b) 0.50 g/cm3
c) 2.44 g/cm3
d) 1.8 g/cm3
e) 0.41 g/cm3
2. Which of the following is a correct interpretation of the results of Rutherford’s experiments in which gold
atoms were bombarded with alpha particles?
a)
b)
c)
d)
e)
Atoms have equal number of positive and negative charges.
Electrons in atoms are arranged in shells.
Neutrons are at the center of an atom.
Neutrons and protons in atoms have nearly equal mass.
The positive charge of an atom is concentrated in a small region.
3. What is the formula of chromium(III) sulfate?
a) Cr3SO4
4.
b) Cr2(SO3)3
c) Cr2SO4
e) Cr2S3
The arrow on the centimeter ruler below is most appropriately read as _____ cm in length.
1
a) 2.472
5.
d) Cr2(SO4)3
b) 2.47
2
c) 2.5
3
d) 2.470
e) 2.50
Report the answer to the following calculation with the correct significant figures.
6.25  ( 7.210  4.30 ) = 71.9375
a) 71.94
6.
b) 7.19 × 102
c) 72
d) 71.9
e) 71.938
What is the chemical formula for the ionic compound formed from the stable ions of Calcium and
nitrogen?
a) CaN3
b) Ca2N3
c) Ca3N2
d) CaN2
e) CaN
4
7.
Iron forms two oxides: Fe2O3 and FeO. What is the correct name of Fe2O3?
a) Ferrous oxide
b) Iron(II) oxide
c) Iron (I) oxide
d) Iron(III) oxide
c) Iron trioxide
8.
Which one of the following correctly matches an acid’s formula with its name?
a) HClO4
b) HClO2
c) HNO3
d) H2SO4
e) HCl(aq)
9.
hydrochloric acid
chlorous acid
nitrous acid
persulfurous acid
hypochloric acid
What is the approximate mass of a single butane molecule?
a) 58 amu
10.
c) 44 amu
d) 56 g
e) 52 amu
The organic compound whose structure is shown below is an example of ____________.
a)
b)
c)
d)
e)
11.
b) 44 g
an alchol
an amine
an alkane
a carboxylic acid
a hydrocarbon
Lithium nitride reacts with water to produce lithium hydroxide and ammonia gas as shown below:
___Li3N(s) + ___H2O(l)  ___ Li+(aq) + ____OH(aq) + ____NH3(g)
When the above equation is balanced and all coefficients reduced to lowest whole number, the
coefficient for OH(aq) is __________________
a) 1
12.
b) 2
c) 3
d) 4
e) 6
When the following reaction is balanced and all coefficients are reduced to lowest whole number, the
coefficient for O2(g) is _________________.
___C10H12O4S(s) + ___O2(g)
a) 6
b) 7
 ___ CO2(g) + ____SO2(g) + ____H2O(l)
c) 12
d) 14
e) 28
5
13.
What is the approximate percent composition of hydrogen in (NH4)2SO4? The formula mass of
(NH4)2SO4 is 132.1 amu.
a) 0.031%
14.
d) 8.1%
d) 73%
b) 101
c) 140
d) 141
e) 162
Which one of the following statement is true?
a)
b)
c)
d)
e)
16.
c) 6.1%
The formula mass for calcium bicarbonate, Ca(HCO3)2 is ______________ amu.
a) 100
15.
b) 3.1%
Compound can be separated into its constituent elements
Compound cannot be separated into its constituent elements
5.0 g of H2 gas and 5.0 g of O2 gas will react to give 10.0 g of water
Alloy is an example of a compound
Rusting is a physical property
Ethylene glycol, the major ingredient in antifreeze, freezes at 11.3 oF. What is the freezing point in
Kelvin?
a) 0 K
b) 261.7 K
c) 220.8 K
d) 284.7 K
e) 325.5 K
6
Part-II: For full credit, show all your work legibly, include units, and report your answer to the correct number
of significant figures. No work shown = 0 points.
17.
(10 pts) Water for irrigation is usually expressed in units of acre-feet. One acre-foot is enough water to
cover one acre of land to a depth of 1.00 foot (1 acre = 43,560 ft2). A water reservoir (lake) has a
maximum capacity of 8.97 x 105 acre-feet. Determine the lake's volume in units of cubic meters.
Assume that the density of water is 1.00 g/cm3 at 25°C, what is the mass of the water in the lake in units
of kilograms.
18.
(8 pts) Fill in the gaps in the following table:
Symbol
# of protons
# of neutrons
15
N38
8
# of electrons
net charge
__________ Total Page 6
2–
26
18
7
19.
(8 pts) Determine whether each of the following molecular pictures represents a homogeneous solution,
a single substance, or a heterogeneous mixture. If the picture represents a single substance, classify each
picture as an element, molecule, or a chemical compound. You might need to use more than one term.
(a)
20.
(b)
(c)
(d)
(4 pts) When lightning strikes, some N2 reacts with O2 to generate NO gas, as shown in the following
molecular picture. Describe how this picture illustrates two postulates of Dalton's Atomic Theory.
A) ______________________________
B) ______________________________
21.
(4 pts) One breathing mixture for deep-sea divers contains 25% molecular oxygen and 75% helium.
Draw a molecular picture of a sample of this mixture that contains six molecules of oxygen.
Key O2 =
Complete the sentence.
My diagram contains
_____________helium _______________.
__________ Total Page 7
8
22.
Potassium metal (density = 0.862 g/mL) has a lustrous silvery appearance. It melts at 336.8 K. It
reacts with chlorine gas to give an ionic solid compound called potassium chloride. Potassium metal is
soft enough to cut with a knife. When added to water, potassium metal reacts with water, often bursting
into flame, and produces an alkaline solution (potassium hydroxide) and generates hydrogen gas.
a) (6 pts) Write two balanced chemical equations that represents the above reactions.
b) (4 pts) From the above description, list two physical properties and two chemical properties.
Physical Properties
23.
Chemical Properties
(4 pts) Fill in the blanks in the following table of acids.
Acid Name
Acid Formula
H2SO4
Hypobromous acid
24.
(6 pts) Fill in the blanks in the following table.
Compound Name
Compound Formula
Ag2O
sulfur tetrafluoride
__________ Total Page 8
Ionic compound or
molecular compound?
9
o
F=
9 o
( C) + 32
5
o
C=
5 o
( F – 32)
9
Kelvin = 0 oC + 273.15
Avogadro’s Number, NA = 6.022  1023
1 ft = 12 in, 1 in = 2.54 cm, 100 cm =1m
Pe rio d ic Ta b le o f t he Ele m e nt s
8A
18
1A
1
3A
13
4A
14
5A
15
6A
16
7A
17
2
He
4 .0 0
5
B
1 0 .8
6
C
1 2 .0
7
N
1 4 .0
8
O
1 6 .0
9
F
1 9 .0
14
Si
2 8 .1
15
P
3 1 .0
16
S
3 2 .1
17
Cl
3 5 .5
30
Zn
6 5 .4
13
Al
2 7 .0
31
Ga
6 9 .7
10
Ne
2 0 .2
18
Ar
3 9 .9
32
Ge
7 2 .6
33
As
7 4 .9
34
Se
7 9 .0
35
Br
7 9 .9
36
Kr
8 3 .8
47
Ag
108
48
Cd
112
49
In
115
50
Sn
119
51
Sb
122
52
Te
128
53
I
127
54
Xe
131
79
Au
197
80
Hg
201
81
Tl
204
82
Pb
207
83
Bi
209
1
H
1 .0 1
2A
2
3
Li
6 .9 4
4
Be
9 .0 1
11
Na
2 3 .0
12
Mg
2 4 .3
3B
3
4B
4
5B
5
6B
6
7B
7
8
9
10
1B
11
2B
12
19
K
3 9 .1
20
Ca
4 0 .1
21
Sc
4 5 .0
22
Ti
4 7 .9
23
V
5 0 .9
24
Cr
5 2 .0
25
Mn
5 4 .9
26
Fe
5 5 .8
27
Co
5 8 .9
28
Ni
5 8 .7
29
Cu
6 3 .5
37
Rb
8 5 .5
38
Sr
8 7 .6
39
Y
8 8 .9
40
Zr
9 1 .2
41
Nb
9 2 .9
42
Mo
9 5 .9
43
Tc
(9 8 )
44
Ru
101
45
Rh
103
46
Pd
106
55
Cs
133
56
Ba
137
57
La
139
72
Hf
178
73
Ta
181
74
W
184
75
Re
186
76
Os
190
77
Ir
192
78
Pt
195
87
Fr
(2 2 3 )
88
Ra
226
89
Ac
227
8B
85
86
84
At
Rn
Po
(2 0 9 ) ( 2 1 0 ) ( 2 2 2 )
109
104
105
106
107
108
110
Mt
Rf
Db
Sg
Bh
Hs
Ds
(2 6 1 ) ( 2 6 2 ) (2 6 3 ) ( 2 6 2 ) ( 2 6 5 ) ( 2 6 6 ) (2 8 1 )
Lant ha nide s
58
Ce
140
59
Pr
141
Act inide s
90
Th
232
91
Pa
231
60
Nd
144
92
U
238
61
62
63
64
65
66
67
68
69
70
71
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
(1 4 5 ) 1 5 0
152
157
159
162
165
167
169 173
175
93
94
95
96
97
98
99
100
101
102
103
Np
Pu
Am
Cm
Bk
Cf
Es
Fm
Md
No
Lr
( 2 3 7 ) ( 2 4 4 ) ( 2 4 3 ) ( 2 4 7 ) ( 2 4 7 ) ( 2 5 1 ) ( 2 5 2 ) ( 2 5 7 ) (2 5 8 ) ( 2 5 9 ) ( 2 6 0 )