1
Exam 2
CHEM 1303.001
Name (print legibly)___________________________________________Seat no.__________
On my honor, I have neither given nor received unauthorized aid on this exam.
Signed
_______________Date ________________
30 questions/3.33 points each
Indicate the BEST answer for the questions in this section by completely filling in the
appropriate space on the answer card with a #2 pencil. Mark only one space per question.
1.
For the reaction: Ag(s)
the oxidizing agent is
+
NO3–(aq)
Ag+(aq)
+
NO(g)
a. Ag(s), since silver increases in oxidation number
b. NO3–(aq), since nitrogen increases in oxidation number
c. NO3–(aq), since oxygen increases in oxidation number
d. NO3–(aq), since nitrogen decreases in oxidation number
e. NO3–(aq), since oxygen decreases in oxidation number
2.
The oxidation number of P in H4P2O7 is
a.
b.
c.
d.
e.
3.
+9
+7
+5
+3
+1
2CuCl
a.
b.
c.
d.
e.
4.
Cu
+
CuCl2
is best classified as what type of reaction?
metal displacement
acid/base
halogen displacement
disproportionation
combination
How many mL of a 2.00 M HCl solution is needed to prepare 500 mL of a 0.250 M
HCl solution?
a.
b.
c.
d.
e.
62.5
250
125
8.00
375
2
5.
How many mL of a 0.150 M KMnO4 solution is needed to titrate 0.400 g of KNO2
(molar mass = 85.1). The balanced net ionic equation for this reaction is
5 NO2– + 2 MnO4– + 6H+
a.
b.
c.
d.
e.
6.
2 Mn2+ + 5 NO3– + 3 H2O
12.5
78.3
31.3
62.7
157
An ideal gas at 20 °C and 2.0 atm pressure occupies a volume of 5.0 L. Calculate the
volume (in L) occupied by this gas at 50 °C and the same pressure.
a.
b.
c.
d.
e.
7.
5.5
0.18
4.5
0.22
11
Which of the following gases will have the greatest density at the same specified
temperature and pressure?
a.
b.
c.
d.
e.
8.
CO
CO2
SO2
SO3
H2
A 2.00-L sample of pure HCl gas at 300 K and 0.100 atm was dissolved in water. It
took 20.3 mL of a NaOH solution to completely neutralize the aqueous HCl. The
molarity of the NaOH solution is
a.
b.
c.
d.
e.
0.400
2.50
0.0328
30.5
0.200
3
9.
A 2.27-g sample of an unknown gas occupies 1.0 L at 300 K and 1.0 atm. The
empirical formula of the compound is CH2. What is the molecular formula of the
compound?
a.
b.
c.
d.
e.
10.
CH2
C2H4
C3H6
C4H8
C5H10
A sample contains only two gases: nitrogen at 1.6 atm pressure and oxygen at 0.40
atm pressure. The mole fraction of oxygen is
a.
b.
c.
d.
e.
11.
0.20
0.25
0.40
0.80
1.2
For the reaction 2NO(g) + O2(g)
2NO2(g)
what volume of oxygen gas at 320 K and 0.900 atm will react completely with 6.0 L
of NO gas at the same temperature and pressure?
a.
b.
c.
d.
e.
12.
1.0
3.0
0.33
6.0
12
An isolated system
a.
b.
c.
d.
e.
13.
allows the transfer of both mass and energy.
allows the transfer of mass but not energy.
allows the transfer of energy but not mass.
does not allow the transfer of either mass or energy.
always operates under conditions of constant pressure.
A 100-g block of aluminum (specific heat = 0.900 J/g °C) at 100.0 °C is placed in
1,000 g of a liquid at 20.0 °C. If the final temperature of the system is 27.0 °C,
calculate the specific heat of the liquid. Assume no heat is lost to the surroundings or
to the vessel containing the liquid.
a.
b.
c.
d.
e.
0.939
1.07
0.0900
11.1
4.18
4
14.
A gas expands in volume from 0.50 L to 0.75 L against a constant pressure of 2.0 atm.
The work done in J (1 L•atm = 101.3 J) is
a.
b.
c.
d.
e.
No work is done, since the pressure is constant.
+ 51 J, since work is done by the system on the surroundings.
– 51 J, since work is done by the system on the surroundings.
+ 51 J, since work is done by the surroundings on the system.
– 51 J, since work is done by the surroundings on the system.
For which of the following reactions does ΔHoreaction equal ΔHof?
15.
a.
b.
c.
d.
e.
16.
H2(g) + S(rhombic)
H2S(g)
C(diamond) + O2(g)
CO2(g)
H2(g) + CuO(s)
H2S(g)
O(g) + O2(g)
O3(g)
2H(g) + O(g)
H2O(g)
Use the following equations
C(graphite) + O2(g)
CO2(g)
2CO(g) + O2(g)
2CO2(g)
ΔH = –394 kJ
ΔH = –566 kJ
to calculate the enthalpy change (in kJ) for the reaction
2C(graphite) + O2(g)
a.
b.
c.
d.
e.
17.
2CO(g)
–222
+172
–960
–1354
+738
Under what conditions is the heat change in a system the same as the enthalpy
change?
a.
b.
c.
d.
e.
constant volume and constant temperature
constant pressure
constant temperature
No work is done.
constant volume
5
–1
18.
The frequency of light (in s ) having a wavelength of 456 nm is
a.
b.
c.
d.
e.
6.58 x 1014
6.58 x 105
6.58 x 10–4
1.52 x 10–15
1.37 x 1020
What is the frequency of light (in s–1) having an energy content of 500 kJ/mol?
19.
a.
b.
c.
d.
e.
20.
7.54 x 1032
1.25 x 1012
1.25 x 1015
7.54 x 1035
7.54 x 1038
The spectral region associated with light of 500 nm is the
a.
b.
c.
d.
e.
21.
ultraviolet
visible
infrared
microwave
radiowave
Which of the following changes in electron configuration would result in emission of
a photon?
a.
b.
c.
d.
e.
22.
1s22s22p4 changes to 1s22s12p5
1s22s22p3 changes to 1s22s02p5
1s22s2 changes to 1s22s1
1s22s22p63s23p0 changes to 1s22s22p63s13p1
1s22s22p63s13p4 changes to 1s22s22p63s23p3
The ground state electron configuration of Ti is
a.
b.
c.
d.
e.
[Ar]4s23d2
[Ar]3d4
[Ar]4s24p2
[Ar]3s23d2
[Ar]4s24d2
6
23.
Which of the following is not an allowed set (n, l, ml, ms) of quantum numbers?
a. 1, 1, 0, – 1
2
b. 2, 1, 0, – 1
2
1
c. 3,
! 2, 1, –
2
1
d. 3,
! 0, 0, –
2
1
e. 2,
! 1, 1, –
2
!
24.
Which
of the following pairs are isoelectronic?
!
a.
b.
c.
d.
e.
V5+, Cl–
B3+, F–
Se+, Br+
Cu2+, Zn+
P3+, S2+
25.
The orbitals pictured above are best described (from left to right) as
a.
b.
c.
d.
e.
26.
dxz, py, s
dxz, pz, s
py, px, s
dxz, px, s
dxz, pxy, s
Which of the following has the most unpaired electrons?
a.
b.
c.
d.
e.
C
C–
C2–
C3–
C4–
7
27.
For an orbital with ml = 4, what is the minimum value allowed for n?
a.
b.
c.
d.
e.
6
5
4
3
2
An element with the electron configuration [Xe]6s24f9 is a(n)
28.
a.
b.
c.
d.
e.
noble gas.
halogen.
alkali metal.
lanthanide (Z = 57 – 71).
actinide (Z = 89 – 103).
The ground state electron configuration of Fe3+ is
29.
a.
b.
c.
d.
e.
30.
[Ar]4s23d3
[Ar]4s24p3
[Ar]4p5
[Ar]3d5
[Ar]3d6
Of the following, which has the largest radius?
a.
b.
c.
d.
e.
O2–
O
S2–
Se2–
Se
8
1A
(1)
1
1
2
H
R =
1.008
3
2A
(2)
4
Li
Be
h =
c =
6.941 9.012
11
12
3
Na
Mg
22.99 24.31
19
20
4
K
Ca
8A
(18)
2
0.0821 L•atm/mol•K
62.4 L•torr/mol•K
–34
6.63 x 10
J• s
8
3.00 x 10 m/s
3A
(13)
5
4A
(14)
6
5A
(15)
7
6A
(16)
8
B
C
N
O
7A
He
(17) 4.003
9
10
F
Ne
10.81 12.01 14.01 16.00 19.00 20.18
13
14
15
16
17
18
3B
(3)
21
4B
(4)
22
5B
(5)
23
6B
(6)
24
7B
(7)
25
…......8B.………
(8)
(9)
(10)
26
27
28
1B
(11)
29
2B
Al
Si
P
S
Cl
Ar
(12) 26.98 28.09 30.97 32.07 35.45 39.95
30
31
32
33
34
35
36
Sc
Ti
V
Cr
Mn
Fe
Cu
Zn
Co
Ni
Ga
Ge
As
Se
Br
Kr
39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.93 58.69 63.55 65.38 69.72 72.61 74.92 78.96 79.90 83.80
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
5 Rb
Sr
Y
Zr
85.47 87.62 88.91 91.22
55
56
57
72
6 Cs
Ba La
Hf
132.9 137.3 138.9 178.5
87
88
89
104
7 Fr
Ra Ac Rf
(223) (226) (227) (261)
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
92.91 95.94 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3
73
74
75
76
77
78
79
80
81
82
83
84
85
86
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
180.9 183.9 186.2 190.2 192.2 195.1 197.0 200.6 204.4 207.2 209.0 (209) (210) (222)
105 106 107 108 109 110 111
Db
Sg
Bh
Hs
Mt
(262) (266) (264) (277) (268)
Ds
Rg
?
(272)
58
59
60
61
62
63
64
65
66
67
68
69
70
71
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
140.1 140.9 144.2 (145) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0
90
91
92
93
94
95
96
97
98
99
100
101
102
103
Th
Pa
U
Np
Pu
Am
Cm
Bk
Cf
Es
Fm
Md
No
Lr
232.0 231.0 238.0 (237) (244) (243) (247) (247) (251) (252) (257) (258) (259) (262)