Dr. Grandinetti
Chemistry 121
Autumn Quarter 1998
FIRST EXAMINATION
Name
Thursday
October 22, 1998
7:30 - 8:48 PM
Rec. Instr.
Two-Digit Section No.
Lab. Instr.
-------------------------------------------------------------------------INSTRUCTIONS
1. First fill out the answer sheet as follows, using #2 pencil only. (Ink will not record).
a) Print your name (Last, First, Middle Initial), starting at the far left. Fill in the corresponding
circles below.
b) Place your signature on the line above your printed name.
c) Print your Social Security Number (without dashes) as the IDENTIFICATION NUMBER, starting at the far left. Fill in the corresponding circles below.
d) Print your two-digit section above your printed name and in the columns “K” and “L” of SPECIAL
CODES. Fill in the corresponding circles below.
Two digit section numbers for lab day, time, and TA.
Monday, 8:30 - 11:30
Lab Instructor
Section No.
Yang, Hsueh-Hui
39
Bullinger, Pat
40
Kahane, Alexandra
41
Pee, Gim-Yang
42
Friday, 8:30 - 11:30
Lab Instructor
Section No.
Yang, Hsueh-Hui
43
Al Taweel, Amany
44
Hudson, Jeffry
45
Cho, Il-Hwan
46
Beegan, Julie
47
Larson, Ben
48
2. After the proctor gives the signal, make certain you have 4 pages with 25 multiple choice questions and
a periodic table.
3. The time allowed is 1 hour and 18 minutes.
4. Only marks on the answer sheet will be graded.
5. When finished hand in only the answer sheet.
Useful Information
Prefix
MegaKiloDeciCentiMilliMicroNanoPicoFemto-
Abbreviation
M
k
d
c
m
µ
n
p
f
Meaning
106
103
10−1
10−2
10−3
10−6
10−9
10−12
10−15
1. [7 points] A sample of matter, found in Australia, was identified as X and was found to consist of
98% silicon and 2% aluminum. Another sample of matter, also identified as X, was found in Texas and
was determined to consist of 90% silicon and 10% aluminum. X is a(n)
a. pure substance
b. element
c. mixture
d. none of these
2. [7 points] Which one of the following is the smallest mass?
a. 25 kg
b. 2.5 × 10−2 Mg c. 2.5 × 1015 pg d. 2.5 × 103 fg
e. 2.5 × 1010 ng
3. [7 points] Which one of the following is true about the liter?
a.
b.
c.
d.
e.
it is the SI base unit for volume
it is equivalent to a cubic decimeter
it is slightly smaller than a quart
it contains 106 cubic centimeters
all are true.
4. [7 points] Which one of the following objects is the most dense?
a.
b.
c.
d.
e.
an object with a volume of 2.5 L and a mass of 12.5 kg
an object with a volume of 139 mL and a mass of 93 g
an object with a volume of 0.00212 m3 and a mass of 4.22 × 104 mg
an object with a volume of 3.91 × 10−24 nm3 and a mass of 7.93 × 10−14 ng
an object with a volume of 13 dm3 and a mass of 1.29 × 103 µg.
5. [7 points] In which one of the following numbers are all of the zeros significant?
a. 100.090090
b. 143.29
c. 0.05843
d. 0.1000
1
e. 00.0030020
6. [7 points] The volume of a regular cylinder, a function of its radius (r) and its height (h), is given by
the formula V = πr2 h. Using the value 3.1416 for the constant π, the volume, in cm3 , of a cylinder of
radius 2.34 cm and height 19.91 cm expressed to the correct number of significant figures in cm3 is
a. 342.49471 cm3
b. 342.495 cm3
c. 342.49 cm3
d. 343 cm3
e. 342 cm3
7. [7 points] How many significant figures should there be in the answer to the following problem?
(29.2 − 20.0)(1.79 × 105 )
=?
1.39
a. 1
b. 2
c. 3
d. 4
e. None of these
8. [7 points] The output of a plant is 4335 pounds of ball bearings per week (5 days). If each ball bearing
weighs 0.0113 g, how many ball bearings does the plant make in a single day? (Use 2.2 lbs = 1 kg).
a. 3.84 × 105
9. [7
a.
b.
c.
d.
e.
b. 7.67 × 104
d. 3.48 × 107
c. 867
e. 2.91 × 106
points] How many electrons, protons, and neutrons are contained in an atom
116 electrons, 116 protons, 92 neutrons
92 electrons, 92 protons, 116 neutrons
24 electrons, 42 protons, 92 neutrons
92 electrons, 92 protons, 24 neutrons
none of the above
10. [7 points] Isotopes are atoms that have the same number of
but differing number of
a. protons, electrons b. neutrons, protons c. protons, neutrons
2
d. electrons, protons
116
92 X?
.
11. [7 points] In the modern periodic table the elements are arranged in
a.
b.
c.
d.
e.
alphabetical order
order of increasing atomic number
order of increasing metallic properties
order of increasing neutron content
None of the above
12. [7 points] Which group in the periodic table contains only nonmetals?
a. 1A
b. 6A
c. 2B
d. 2A
e. 8A
13. [7 points] Which one of the following should be the most similar to strontium in chemical and physical
properties?
a. Li
b. At
c. Rb
d. Ba
e. Cs
14. [7 points] Which one of the following molecular formulas is also an empirical formula?
a. C6 H6 O2
b. C2 H6 SO
c. H2 O2
d. H2 P4 O6
15. [7 points] When a metal and a nonmetal react, the
to gain electrons.
a.
b.
c.
d.
e.
e. C6 H6
tends to lose electrons and the
metal, metal
nonmetal, nonmetal
metal, nonmetal
nonmetal, metal
none of these, these elements share electrons
16. [7 points] Which one of the following contains the greatest number of electrons?
a. P3+
b. P
c. P2−
d. P3−
3
e. P2+
tends
17. [7 points] Of the choices below, which one is not an ionic compound?
a. PCl5
b. MoCl6
c. RbCl
d. PbCl2
e. all are ionic compounds
18. [7 points] What is the formula of the compound formed between strontium ions and nitrogen ions?
a. SrN
b. Sr3 N2
c. Sr2 N3
d. SrN2
e. SrN3
19. [7 points] The correct formula for molybdenum(IV) hypochlorite is
a. Mo(ClO3 )4
b. Mo(ClO)4
c. Mo(ClO2 )4
d. Mo(ClO4 )4
e. None are correct
20. [7 points] The correct name for CrCl3 is
a.
b.
c.
d.
e.
chromium chlorine
chromium(III) chloride
monochromium trichloride
chromium(III) trichloride
none of these
21. [7 points] The atomic masses in the periodic table are not exact numbers. For example, carbon is
listed as 12.01115 instead of 12.00000. Why?
a.
b.
c.
d.
e.
our technology does not allow for exact measurement of such a small quantity
atoms gain and lose electrons easily and that changes their masses significantly
atomic masses listed in the periodic table are weighted averages of isotopic masses
atomic masses are measured in real samples that are always contaminated with other elements
none of these are the correct reason
22. [7 points] The average atomic weight of copper is 63.5. Copper has two naturally occurring isotopes.
One of the isotopes has an atomic weight of 62.9 and an abundance of 69.1%. The other isotope has
an abundance of 30.9%. What is the atomic weight of this isotope?
a. 63.2 amu
b. 63.8 amu
c. 64.1 amu
4
d. 64.8 amu
e. none of these
23. [7 points] The mass percentage of Al in aluminum sulfate is
a. 7.886%
b. 15.77%
c. 21.93%
d. 45.70%
e. 35.94%
24. [7 points] A compound with a molecular weight of 110.1 that contained only C, H, and O was analyzed
by combustion. The combustion of a 5.19 g sample of the compound resulted in the formation of 12.4
g of carbon dioxide and 2.55 g of water. What is the molecular formula of this compound?
a. C6 H6 O2
b. C3 H3 O
c. CH3 O
d. C2 H6 O5
e. none of these
25. [7 points] C2 H2 burns in O2 to produce CO2 and H2 O according to the following equation.
C 2 H2 +
O2 →
CO2 +
H2 O
Balance the equation above and calculate how many grams of CO2 will be formed when 3.0 g of C2 H2
reacts with 3.0 g of O2 ?
a. 2.8
b. 4.1
c. 6.2
d. 9.4
5
e. none of these
7
6
5
4
3
2
1
H
Y
La
Ac
Actinium
89
227.03
Lanthanum
57
138.91
Yttrium
39
88.91
Actinide Series
Zr
Hf
V
24
Cr
52.00
VIB
Nb
Ta
W
231.0359
Pa
232.04
Th
Thorium
90
91
Protactinium
Nd
Praseodymium
Ce
Cerium
U
Uranium
92
238.03
60
Neodymium
144.24
Tungsten
74
183.85
Mo
Re
Np
Os
Sm
Pu
94
(244)
Samarium
62
150.36
Osmium
76
190.2
Ru
101.1
Iron
Fe
Co
Rh
Ir
Eu
Ni
Pd
Pt
Gd
64
157.25
Platinium
78
195.08
Palladium
46
106.4
Nickel
28
58.69
95
Am
(243)
Curium
Cm
96
(247)
Europium Gadolinium
63
151.96
Iridium
77
192.2
Rhodium
45
102.91
Cobalt
27
58.93
VIIIB
Neptunium Plutonium Americium
93
237.05
Pm
61
Promethium
(145)
Rhenium
75
186.2
Tc
(98)
26
55.85
42
43
44
Molybdenum Technetium Ruthenium
95.94
59Pr
Tantalum
73
180.95
Niobium
41
92.91
140.9077
58
Mn
25
54.94
VIIB
Vanadium Chromium Manganese
23
50.94
VB
140.12
Hafnium
72
178.49
Zirconium
40
91.22
Ti
Titanium
Sc
22
47.88
IVB
Scandium
21
44.96
IIIB
Lanthanide Series
Rd
Radium
Fr
Francium
88
226.03
(223)
87
Ba
Barium
Cs
Cesium
56
137.33
132.91
55
Sr
38
Strontium
Rubidium
87.62
37Rb
85.47
Ca
Calcium
20
Potassium
K
40.08
39.098
19
Mg
Magnesium
Na
Sodium
12
24.305
22.990
11
Be
Berylium
Li
4
9.012
IIA
Lithium
3
6.941
Hydrogen
1
1.008
IA
}
Cu
Ag
Tb
Cd
Hg
66
Dy
162.50
Mercury
80
200.59
Cadmium
48
112.41
Zinc
Zn
30
65.38
IIB
Si
Ga
In
Tl
Ho
67
164.93
Thallium
81
204.38
Indium
49
114.82
Gallium
31
69.72
Bk
98
Cf
(251)
99
Es
(254)
Pb
Er
100
Fm
(257)
Erbium
68
167.26
Lead
82
207.2
Tin
Sn
50
118.69
P
As
Sb
Bi
Tm
101
Md
(258)
Thullium
69
168.93
Bismuth
83
208.98
Antimony
51
121.75
Arsenic
33
74.92
Phosphorus
15
30.974
O
S
Se
Te
Po
Yb
102
No
(259)
Ytterbium
70
173.04
Polonium
84
(244)
Tellurium
52
127.60
Selenium
34
78.96
Sulfur
16
32.06
Oxygen
8
15.999
VIA
F
Cl
Br
I
At
Lu
103
Lr
(260)
Lutetium
71
174.97
Astatine
85
(210)
Iodine
53
126.90
Bromine
35
79.904
Chlorine
17
35.453
Fluorine
9
18.998
VIIA
Berkelium Californium Einsteinium Fermium Mendelevium Nobellium Lawrencium
97
(247)
Ge
Germanium
32
72.59
14
Silicon
Al
13
Aluminum
Terbium Dysprosium Holmium
65
158.93
Gold
Au
79
196.97
Silver
47
107.87
Copper
29
63.546
IB
28.09
26.98
Nitrogen
7
N
C
6
Carbon
B
Boron
5
14.007
12.011
10.81
VA
IVA
IIIA
He
Ne
Ar
Kr
Xe
Rn
Radon
86
(222)
Xenon
54
131.29
Krypton
36
83.80
Argon
18
39.948
Neon
10
20.179
Helium
2
4.003
VIIIA