(Circle the Alphabet Segment of Your LAST NAME): A,B C-H I-M N-S T-Z

CHEM 107 (Spring-2004)

Exam 3 (102 pts)

Name: ------, SSN ------

LAST NAME, First

(Circle the alphabet segment of your LAST NAME): A,B C-H I-M N-S T-Z

Please answer the following questions:

Part I: Multiple Choices (56 pts: 14 @ 4 pts each). Circle the ONE best answer:

1. Consider four identical 1.0 L flasks containing the following gases each at 25 °C and 1 atm pressure. Which gas do the molecules have the greatest average kinetic energy?

a) H2b) O2

c) NH3d) same for all gases

Which of the following equations DO NOT represent an oxidation?

a)SO2 SO3b) Mg Mg2+

c)MnO2Mn2+d) 2 Br- Br2

The oxidation states of chlorine in SO32- and H2S are:

a)+4 and -2, respectively b) +6 and –2, respectively

c) -4 and +2, respectively d) +2 and –2, respectively

4. Which set of temperature and pressure conditions will cause a gas to exhibit the greatest deviation from the ideal behavior?

a) 100 ºC and 4 atmb) 100 ºC and 2 atm

c) -100 ºC and 4 atmd) 0 ºC and 4 atm

5. Calculate the wavelength, in meters, of microwave radiation that corresponds to an energy of 2.63 J/mol photons.

a) 2.63 b) 4.55 x 10-2

c) 1.14 x 108d) none of the above

6. Which of the following electromagnetic radiation has the shortest frequency?

a) X-ray b) Visible light

c) Radio waved) Infrared

7. Which of the following isoelectronic species would have the smallest radius?

a) Mg2+b) N3-

c) O2-d) F-

8. The orbital of 2p electrons is often represented as being

a) elliptical b) square

c) dumbbell shaped d) spherical

9. Which of the following would cause a reduction in the volume of a gas?

a)Increasing the number of molecules (constant P& T)

b)Decreasing the pressure (constant n & T)

c)Decreasing the temperature (constant n & P)

d)Increasing the kinetic energy (constant n & P)

10. Which set of quantum numbers is correct and consistent with n = 4?

a) ℓ = 2, mℓ = -3, ms = +½

b) ℓ = 4, mℓ = -5, ms = -½

c)ℓ = 3, mℓ = +3, ms = +½

d) ℓ = 3, mℓ = -3, ms = +1

11. An Ag+ ion is

a)paramagnetic with two unpaired electrons

b)diamagnetic with zero unpaired electrons

c)paramagnetic with three unpaired electrons

d)paramagnetic with one unpaired electron

12. The ground state electron configuration of iridium, Ir (Z = 77) is

a)[Xe] 5d76s2

b) [Xe] 4f14 5d76s2

c) [Xe] 4f14 5d86s1

d) [Xe] 4f14 5d9

13. The maximum number of electrons in the 4dsubshellis

a)6 b) 14

c) 2 d) 10

14. The ground state electron configuration of chromium atom, Ni (Z = 28) is

a) 1s2 2s2 2p6 3s2 3p6 3d10

b) 1s2 2s2 2p6 3s2 3p64s23d8

c) 1s2 2s2 2p6 3s2 3p6 3d5 4s2 4p3

d) 1s2 2s2 2p6 3s2 3p6 4s13d9

Part II. (10 pts) Equations and formulas

Balance the following unbalanced redox equation in acidic solution:

O2 (g) + Br- (aq) H2O (l) + Br2 (l)

Then indicate:

a) The oxidation step: ------

b) The reduction step: ------

c) The oxidizing agent: ------

d) Substance that is reduced: ------

d)The number of electrons that is transferred per mole of the reducing agent: ------

______

Part III. Calculations (36 pts: 3 @ 12 pts each) Show all work for full credit. Please express all answers with the proper units and correct number of significant figures.

1. a) Calculate the wavelength in nanometers in the H-atom spectrum that arises from the electrontransition of n = 5 to n = 2.

b) In what spectral region does this transition occur? ------

c) Is energy absorbed or emitted? ------

d) How many emission lines are possible for the transition from n =5 to lower energy levels? ------

2. Calculate the density of nitric oxide gas, NOat 27ºC and 700 torr.

3. Nitric acid can be prepared by bubbling dinitrogen pentoxide, N2O5 into water.

N2O5 (g) + H2O (aq) 2 H+ (aq) + 2 NO3- (aq)

(a)How many moles of H+ are obtained when 1.50 L of N2O5 at 25º C and 1.00 atm pressure is bubbled into water?

(b)The solution obtained in (a) after reaction is complete has a volume of 437 mL. What is the molarity of the nitric acid obtained?

Exam 3 – Spring 2004

You will have 70 minutes to complete this exam. The exam has 4 pages plus the Periodic Table and Reference page.

When you are told to do so, tear off the Periodic Table cover sheet and use as required during the exam.

1 / 1
H
1.01 / Periodic Table of the Elements / 2
He
4.00
2 / 3
Li
6.94 / 4
Be
9.01 / 5
B
10.81 / 6
C
12.01 / 7
N
14.01 / 8
O
16.00 / 9
F
19.00 / 10
Ne
20.18
3 / 11
Na
22.99 / 12
Mg
24.30 / 13
Al
26.98 / 14
Si
28.08 / 15
P
30.97 / 16
S
32.06 / 17
Cl
35.45 / 18
Ar
39.95
4 / 19
K
39.1 / 20
Ca
40.08 / 21
Sc
44.96 / 22
Ti
47.88 / 23
V
50.94 / 24
Cr
52.00 / 25
Mn
54.94 / 26
Fe
55.85 / 27
Co
58.93 / 28
Ni
58.69 / 29
Cu
63.55 / 30
Zn
65.38 / 31
Ga
69.72 / 32
Ge
72.59 / 33
As
74.92 / 34
Se
78.96 / 35
Br
79.90 / 36
Kr
83.80
5 / 37
Rb
85.47 / 38
Sr
87.62 / 39
Y
88.91 / 40
Zr
91.22 / 41
Nb
92.91 / 42
Mo
95.94 / 43
Tc
(98) / 44
Ru
101.1 / 45
Rh
102.9 / 46
Pd
106.4 / 47
Ag
107.9 / 48
Cd
112.4 / 49
In
114.8 / 50
Sn
118.7 / 51
Sb
121.8 / 52
Te
127.6 / 53
I
126.9 / 54
Xe
131.1
6 / 55
Cs
132.9 / 56
Ba
137.3 / 57
La
138.9 / 72
Hf
178.5 / 73
Ta
181.0 / 74
W
183.8 / 75
Re
186.2 / 76
Os
190.2 / 77
Ir
192.2 / 78
Pt
195.1 / 79
Au
197.0 / 80
Hg
200.6 / 81
Tl
204.4 / 82
Pb
207.2 / 83
Bi
209.0 / 84
Po
(209) / 85
At
(210) / 86
Rn
(222)
7 / 87
Fr
(223) / 88
Ra
226.0 / 89
Ac
227.0 / 104
Rf
(261) / 105
Db
(262) / 106
Sg
(263) / 107
Bh
(262) / 108
Hs
(265) / 109
Mt
(266) / 110
Uun
(269) / 111
Uuu
(272) / 112
Uub
(277)
58
Ce
140.1 / 59
Pr
140.9 / 60
Nd
144.2 / 61
Pm
(145) / 62
Sm
150.4 / 63
Eu
152.0 / 64
Gd
157.2 / 65
Tb
158.9 / 66
Dy
162.5 / 67
Ho
164.9 / 68
Er
167.3 / 69
Tm
168.9 / 70
Yb
173.0 / 71
Lu
175.0
90
Th
232.0 / 91
Pa
231.0 / 92
U
238.0 / 93
Np
237.0 / 94
Pu
(244) / 95
Am
(243) / 96
Cm
(247) / 97
Bk
(247) / 98
Cf
(251) / 99
Es
(252) / 100
Fm
(257) / 101
Md
(258) / 102
No
(259) / 103
Lr
(260)