Chemistry 12
Exam II Form A
February 28, 2001
Name
____________________
Section
____________________
Student No. ____________________
IMPORTANT: On the scantron (answer sheet), you MUST clearly fill your name, your
student number, section number, and test form (white cover = test form A; yellow cover =
test form B). Use a #2 pencil.
1. From the following heats of reaction:
2SO2 (g) + O2 (g) ! 2SO3 (g)
2S (s) + 3O2 (g) ! 2SO3 (g)
∆H = −196 kJ
∆H = −790 kJ
calculate the heat of reaction to form SO2 from sulfur and oxygen according to the following
equation:
S (s) + O2 (g) ! SO2 (g)
a. + 395 kJ
b. + 202 kJ
c. −297 kJ
d. −398 kJ
e. −594 kJ
___________________________________________________________________________
2. Calculate ∆Horxn for neutralization reaction that occurs between NaOH and HCl.
∆Hof (NaOH) (aq) = −469.6 kJ/mol ∆Hof (NaCl)(aq) = −407.1 kJ/mol
∆Hof (HCl) (aq) = −167.2 kJ/mol
∆Hof (H2O) (l) = –285.8 kJ/mol
There are 25 questions on this exam. Check that you have done all of the problems and filled in
the first 25 bubbles on the scantron. The maximum score on this exam is 20 points.
•
•
Calculators with text-programmable memory are not allowed.
Relevant data and formulas, including the periodic table, are attached at the end of this
exam.
Your grade will be based only on what is on the scantron form.
The answer key will be posted on the web after the exam (under "News").
Hints
•
•
+515.5 kJ
–390.5 kJ
–1329.7 kJ
+29.1 kJ
–56.1 kJ
_____________________________________________________________________________
Exam policy
•
•
a.
b.
c.
d.
e.
As you read the question, underline or circle key words to highlight them for yourself.
Avoid errors from "mis-reading" the question.
There is no penalty for guessing.
1
3. Which of the following is the ground-state electron configuration of K+?
a.
b.
c.
d.
e.
[Ar]4s1
[Ar]3d10
[Ar]4s2
[Ar]
[Ar]4s13d1
______________________________________________________________________________
2
4. How much energy is required to heat 20 g of water from 22 oC to 37 oC? The specific heat of
water is 4.18 J/(gK).
a.
b.
c.
d.
e.
8. The first four ionization energies (I) for an atom are given below.
I1: 578
1839 J
1254 J
3093 J
177 J
105 J
I2: 1820
I3: 2750
I4: 11,600
(all in kJ/mol)
What is the atom represented?
______________________________________________________________________________
a.
b.
c.
d.
e.
sodium
aluminum
chlorine
silicon
neon
5. How many unpaired electrons are there in the ground-state of Cu?
___________________________________________________________________________
a.
b.
c.
d.
e.
0
1
2
3
4
9. Which of the following atoms is the most electronegative?
______________________________________________________________________________
6. Which of the following ionic solids has the largest lattice energy?
a.
b.
c.
d.
e.
LiCl
KCl
RbCl
BaO
SrO
a. francium
b. lithium
c. chlorine
d. oxygen
e. fluorine
___________________________________________________________________________
10. Which of the following species has the smallest radius?
______________________________________________________________________________
7. A Lewis structure of SO3 is shown below. How many additional resonance structures
equivalent to the one shown can be drawn for this molecule?
a.
b.
c.
d.
e.
Ne
F–
O2–
Cl
Cl–
____________________________________________________________________________
11. Which of the following bonds will be non-polar?
O
O
a.
b.
c.
d.
e.
S
O
none
one
two
three
four
a.
b.
c.
d.
e.
Li─H
H─F
H─Cl
O─O
O─H
_____________________________________________________________________________
______________________________________________________________________________
3
4
12. The following pictures present s (I), p (II), d (III), and f (IV) orbitals. Which of these orbitals
can have the quantum number ml = −2?
I)
15. Which of the following is a permissible set of quantum numbers?
a.
b.
c.
d.
e.
II)
n
2
3
2
3
2
l
−1
2
−3
2
3
ml
+2
−3
−2
−2
0
ms
+1/2
−1/2
−1/2
+1/2
+1/2
__________________________________________________________________________________________
III)
IV)
16. Which of the following orderings of atom/ion radii is incorrect?
a. I– > I > I+
b. Ca2+ > Mg2+ > Be2+
c. Fe > Fe2+ > Fe3+
d. K+ > Cl– > S2–
e. Br > Cl > F
____________________________________________________________________________
a. III only
b. II and III only
c. IV only
d. III and IV only
e. I, II, III and IV
____________________________________________________________________________
13. Which of the following photons of the electromagnetic radiation has the highest energy?
a. orange light with λ = 645 nm
b. radio-wave with frequency of 700 MHz (λ = 43 cm)
c. microwave with λ = 2 cm
d. ultraviolet light with frequency of 3 x 1015 s-1 (λ = 100 nm)
e. infrared light with λ = 6 µm (= 6 x 10-6 m)
__________________________________________________________________________
14. Of the following isoelectronic species, which one has the smallest size?
a. S2–
b. Cl–
c. Ar
d. K+
e. Ca2+
______________________________________________________________________________
5
17. Bromine is much more apt to exist as an anion than is potassium. This is because:
a.
b.
c.
d.
e.
Bromine is bigger than potassium.
Bromine has greater (more positive) ionization energy than potassium does.
Bromine has greater (more negative) electron affinity than potassium does.
Bromine is a gas and potassium is a solid.
Bromine is more metallic than potassium.
______________________________________________________________________________
18. Based on the positions of the elements in the periodic table, which of the following bonds is
the most polar?
a.
b.
c.
d.
e.
P─N
P─O
P─Si
P─S
P─C
______________________________________________________________________________
6
19. What is the formal charge on phosphorus in the following Lewis structure of PO43─?
3-
O
O
a.
b.
c.
d.
e.
P O
O
a. –2
b. –1
c. 0
d. +1
e. +2
_____________________________________________________________________________
20. Which of the following drawings is the best Lewis structure for nitrate ion (NO3–)? Other
structures (that are equally good) may exist, but are not shown here.
a.
O
N
O
O
b.
O
N
O
N
d.
O
O
N
O
-
O
-
O
c.
O
-
4s
4p
4d
4f
5s
_____________________________________________________________________________
23. Which quantum number defines the shape of the orbital?
a.
b.
c.
d.
e.
principal (n)
azimuthal (l)
magnetic (ml)
spin (ms)
magnetic and spin (ml and ms)
_____________________________________________________________________________
-
O
22. In a given multielectron atom, which subshell electrons experience the largest effective
nuclear charge?
e.
O
N
O
24. What is the value of the azimuthal quantum number (l) for the outermost electrons in a
ground state oxygen atom?
a.
b.
c.
d.
e.
0
1
2
3
4
______________________________________________________________________________
25. Which of the following transitions in the Bohr hydrogen atom affords emission of the
highest-energy photon?
O
__________________________________________________________________________
21. Which of the following statements is false?
a. Metals tend to have lower ionization energies than nonmetals
b. A neutral element that readily accepts electrons, such as F, has an exothermic electron
affinity.
c. When a neutral atom loses an electron, its radius increases.
d. Nonmetals are more electronegative than metals.
e. As one goes across a period from left to right, the radii of the neutral atoms generally
decrease.
_____________________________________________________________________________
7
a. ni = 1 ! nf = 4
b. ni = 4 ! nf = 1
c. ni = 4 ! nf = 2
d. ni = 2 ! nf = 4
e. ni = 1 ! nf = 2
______________________________________________________________________________
END OF EXAM
8
PERIODIC TABLE of the ELEMENTS (2001)
Constants & Equations
2
-2
MAIN GROUPS
1 J = 1 kg· m ·s
RH = 2.18 × 10-18 J
c = 3.00 × 108 m·s-1
e = –1.60 × 10-19 C
h = 6.63 × 10-34 J·s
23
N = 6.02 × 10 mol
1 D = 3.33 × 10-30 C·m
-1
H
1.008
3
E = hν
 1
1 
∆E = R H  2 − 2 
n
n
 i
f 
λ=
h
mv
E = kL
Q1Q2
d
q = m · c · ∆T
2A
2
4
Li
Be
9.012
11
Mg
24.305
20
5B
5
23
V
Cr
Mn
47.867
50.942
51.996
54.938
K
Ca
Sc
40.078
44.956
Ti
Co
8B
10
28
Ni
55.845
58.933
58.693
14.007
15.999
18.998
20.180
45
46
C
N
O
10
13
14
15
16
S
Cl
Ar
26.982
28.086
30.974
32.066
35.453
39.948
Cu
Zn
Ga
Ge
As
Se
Br
Kr
63.546
65.39
69.723
72.61
74.992
78.96
79.904
83.80
1B
11
29
31
Si
32
33
35
18
36
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
48
49
In
Sn
Sb
Te
52
53
I
Xe
92.906
95.94
[98]
101.07
102.90
106.42
107.87
112.41
114.82
118.71
121.76
127.60
126.90
131.29
83
84
85
54
Cs
Ba
La*
Hf
Ta
73
74
W
Re
Os
76
77
Ir
Pt
Au
Hg
80
81
Tl
Pb
Bi
Po
At
Rn
132.91
137.33
138.91
178.49
180.95
183.84
186.21
190.23
192.22
195.08
196.97
200.59
204.38
207.2
208.98
[209]
[210]
[222]
88
82
51
34
17
91.224
79
50
P
Y
78
47
Al
39
86
Fr
Ra
Ac**
89
104
105
106
107
108
109
110
111
112
114
116
118
[223]
[226]
[227]
[261]
[262]
[266]
[264]
[265]
[268]
[269]
[272]
[277]
[285]
[289]
[293]
Rf
Db
58
* LANTHANOIDS
Sg
59
Bh
60
Hs
61
Mt
62
63
64
65
66
67
68
69
70
71
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
140.12
140.91
144.24
[145]
150.36
151.96
157.25
158.92
162.50
164.93
167.26
168.93
173.04
174.97
90
Th
Pa
91
92
U
Np
Pu
Am
Cm
Bk
Cf
Es
Fm
Md
101
102
103
232.04
321.04
238.03
[237]
93
[244]
94
[243]
95
[247]
[247]
[251]
[252]
[257]
[258]
[259]
[262]
10
9
Ne
12.011
88.906
75
44
F
10.811
38
72
43
4.003
Sr
57
42
7A
17
9
87.62
56
41
6A
16
8
Rb
55
40
Fe
8B
9
27
8B
8
26
5A
15
7
85.468
** ACTINOIDS
∆H°rxn = Σ n ∆H°f (products) − Σ m ∆H°f (reactants)
7B
7
25
4B
4
22
39.098
37
6B
6
24
3B
3
21
4A
14
6
2B
12
30
12
Na
He
3A
13
5
B
TRANSITION METALS
22.990
87
µ = Qr
8A
18
2
6.941
19
c = λν
MAIN GROUPS
1A
1
1
96
97
98
99
100
No
Lr
ANSWER KEY
Chem 12 Exam II
Spring 2001
1. C
2. E
3. D
4. B
5. B
6. E
7. C
8. B
9. E
10. A
11. D
12. D
13. D
14. E
15. D
16. D
17. C
18. B
19. C
20. D
21. C
22. A
23. B
24. B
25. B
11