Chemistry 111 Sect. 2
Exam #1
February 28, 2002
Name: ________________________________________________
Student #: ______________________________________________
Please put your name and student number on all pages in case they become separated. The
last page of the exam has some useful information. The exam lasts 60 minutes. There are a
total of 100 points.
MULTIPLE CHOICE QUESTIONS
Place an X in the box corresponding to the correct answer.
1. (5 pts)
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The formula for cobalt (III) nitrate is:
Co(NO2)3
Co3(NO2)2
CoNO3
Co(NO3)3
Co3(NO3)2
2. (5 pts) An ion with the symbol 23592U3+ is correctly described by which of the following?
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(protons, neutrons, electrons)
92, 235, 92
92, 143, 89
92, 143, 95
143, 92, 235
235, 65, 143
3. (5 pts) A series of measured lengths is added together as shown. The correct value to
report is:
10.11111 cm + 1.02 cm + 100.00001 cm + 0.04000 cm = 111.17112 cm
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111.17112 cm
111.1711 cm
111.171 cm
111.17 cm
111.2 cm
Page 1
Chemistry 111 Sect. 2
Exam #1
February 28, 2002
Name: ________________________________________________
Student #: ______________________________________________
4. (5 pts) A photon of light strikes a hydrogen atom and causes the electron in the atom to
transition from level n=2 to level n=4. What is the energy of the photon?
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-4.1×10-19 J
-1.4×10-19 J
1.4×10-19 J
4.1×10-19 J
2.2×10-18 J
5. (5 pts) A compound of boron and hydrogen is 81.1% boron by weight. What is the
empirical formula of the compound?
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BH3
BH5
BH10
B2H5
B2H10
6. (5 pts) A reaction between nitrogen and water produces two products. The balanced
chemical equation for the reaction is shown below with one of the products left blank. What
is the missing product?
2 N2 + 6 H2O
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→
4 _____ + 3 O2
H2
NO
NH6
NH3
N2H4
Page 2
Chemistry 111 Sect. 2
Exam #1
February 28, 2002
Name: ________________________________________________
Student #: ______________________________________________
7. (5 pts) Which has the longer wavelength, an electron moving with a speed of 2 × 106 m/sec
or a neutron moving at the same speed? Note: me = 9.1 × 10-28 g, mn = 1.7 × 10-24 g.
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the electron has longer wavelength
the neutron has longer wavelength
they have the same wavelength
neither has a wavelength
can’t tell from the information given
8. (5 pts) The element in group 5A, period 3 is:
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indium
nitrogen
phosphorus
potassium
scandium
MULTIPLE MULTIPLE CHOICE QUESTIONS
Place an X in the boxes corresponding to the correct answers. Any number of answers may
be correct, including none of them.
9. (10 pts) Consider the properties of electromagnetic radiation: energy (E), frequency (ν)
and wavelength (λ). Which of the following ways to plot will give a linear graph?
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λ vs. ν
E vs. ν
E vs. λ
λ vs. 1/ν
E vs. 1/ν
Page 3
Chemistry 111 Sect. 2
Exam #1
February 28, 2002
Name: ________________________________________________
Student #: ______________________________________________
10. (10 pts) Which of the following is not a metal?
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argon
chlorine
silicon
sodium
sulfur
11. (10 pts) Which of the following are TRUE?
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1/2 mole of Cl2 contains 3.0 × 1023 atoms of chlorine
the density of hydrogen gas at room temperature and atmospheric pressure is less
than
that of air
cations always carry negative net electric charge
50 °C is a lower temperature than 50 K
the radius of the lowest energy Bohr orbital in hydrogen is 2.3 nm
SHORT ANSWER QUESTIONS
Answer in the spaces indicated.
12. (10 pts)
What is the name of the alkali metal that is in period 7? __________________________
What is the name of the halogen that is in period 4? _____________________________
What is the name of the alkaline earth metal that is in period 4? ___________________
What is the name of the noble gas that is in period 1? ___________________________
What is the name of the anion ClO-? _________________________________________
Page 4
Chemistry 111 Sect. 2
Name: ________________________________________________
Exam #1
Student #: ______________________________________________
February 28, 2002
13. (10 pts) As we saw in class, aluminum reacts with bromine to produce solid aluminum
bromide. If 2.7 g of Al foil is placed in an excess volume of Br2, how many grams of
aluminum bromide will be formed?
2 Al(s) + 3 Br2(l) → Al2Br6(s)
14. (10 pts) You weigh a lump of metal and find its mass to be 340.00 grams. The metal
lump, when dropped in a beaker completely full of water, displaces 1.7 mL of water. What is
the density of the metal? (Report your answer to the correct number of significant figures
and include units.)
Page 5
Chemistry 111 Sect. 2
Exam #1
February 28, 2002
Name: ________________________________________________
Student #: ______________________________________________
Useful information
NA = 6.02 × 1023 molecules/mol
d = m/V
c = 3.0 × 108 m/sec
E = -Rhc/n2
h = 6.6 × 10-34 J sec
Rhc = 2.2 × 10-18 J
me = 9.1 × 10-28 g
a0 = 0.0529 nm
E = hν
c = λν
λ = h/(m v)
PERIODIC TABLE OF THE ELEMENTS
IA
IIA
IIIB
IVB
VB
VIB
VIIB
VIIIB
IB
IIB
IIIA
IVA
VA
VIA
VIIA VIIIA
1
2
H
He
1.008
4.003
3
4
5
Li
Be
B
C
N
O
F
Ne
6.939
9.012
10.81
12.01
14.01
16.00
19.00
20.18
11
12
13
14
15
16
17
18
Na
Mg
Al
Si
P
S
Cl
Ar
22.99
24.31
26.98
28.09
30.97
32.07
35.45
39.95
19
20
21
22
K
Ca
Sc
Ti
39.10
40.08
44.96
37
38
39
Rb
Sr
85.47
55
23
6
7
8
9
10
24
25
26
27
28
29
30
31
32
33
34
35
36
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
47.90
50.94
52.00
54.94
55.85
58.93
58.71
63.55
65.39
69.72
72.61
74.92
78.96
79.90
83.80
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
87.62
88.91
91.22
92.91
95.94
(99)
101.1
102.9
106.4
107.9
112.4
114.8
118.7
121.8
127.6
126.9
131.3
56
57
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
132.9
137.3
138.9
178.5
181.0
183.8
186.2
190.2
192.2
195.1
197.0
200.6
204.4
207.2
209.0
(209)
(210)
(222)
87
88
89
Fr
Ra
Ac
(223)
226.0
227.0
Page 6
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