Dr. Irmi Schewe-Miller CHEM 177 Name: Dr. Robbyn Anand ......sheet. Questions are written on both...
Transcript of Dr. Irmi Schewe-Miller CHEM 177 Name: Dr. Robbyn Anand ......sheet. Questions are written on both...
-
1
Dr. Irmi Schewe-Miller Dr. Robbyn Anand This exam consists of two sections on 8 pages
CHEM 177 Exam II
March 6, 2017
Name:__________________ Recitation TA:___________ Recitation Section:_________
For Section I (p. 3-4, 36 points): The answer you fill in on your bubble sheet is the one that will be scored. You can circle the answer on this exam booklet for your own reference; however, none of it will be graded unless they are correctly bubbled in your computer bubble sheet. Questions are written on both sides of each page. The last page of the exam is blank and can be used as scratch paper. It must be turned in with your exam! For Section II (p. 5-6, 18 points): In this section, answers are handwritten. Show all of your work on these exam pages. If the grader cannot read your writing, you may not receive credit for the work shown. Numerical answers should be given in the correct number of significant figures and units. TA/Instructor use only. Score: Section I ________/36 Section II _______/18 Total _______/54 _______%
If you do not correctly bubble-in your ISU email ID and your recitation section number, your exam score will NOT get uploaded into blackboard gradebook and you will receive a score of ‘0’. Do not use mechanical pencils. Only #2 pencils are highly recommended. Regrade Policy: Graded exam will be returned to you during Thursday recitation. If you have request for regrade, you MUST submit your exam to your TA before leaving the recitation room.
-
2
There are 8 pages to this exam. You can safely tear the last page that contains the table of solubility guidelines and a periodic table. Check to make sure you have a complete exam. During the exam, all electronic devices (except calculator), textbook, notes, etc. must be put away and completely out of sight. Any kind of academic dishonesty will not be tolerated and it will be reported to the Dean of Students and your academic adviser. Incidents of academic dishonesty may result in F grade for this course. Exam Room Teaching Assistant Section(s) Recitation Time
Troxel 1001 Scott Carnahan 4, 17 9:00 a.m., 10:00 a.m.
Calvin Conn 8, 15 11:00 a.m., 8:00 a.m.
Miranda Emaus 7, 11, 20 11:00 a.m., 1:10 p.m., 12:10 p.m.
LeBaron 1210 Patrick Heintz 3, 21 9:00 a.m., 12:10 p.m.
Saad Tarik 6, 19 10:00 a.m., 11:00 a.m.
Nicole Stephens 22, 23 1:10 p.m., 2:10 p.m.
Gilman 1002 Xuechen Luan 5, 16 10:00 a.m., 9:00 a.m.
Eric Testroet 10, 13 1:10 p.m., 2:10 p.m.
Gilman 1352 Isaac Young 2, 18 8:00 a.m., 10:00 a.m.
Zachary Robole 14 8:00 a.m.
-
3
Section I: Multiple Choice. You may choose only 1 answer to the following questions. All responses must be filled in on the bubble sheet. The point value of each question is written next to the question.
1. (3 pts) Of the following, which one is a state function?
A) q B) E C) w D) heat
2. (3 pts) Aqueous sodium sulfate (Na2SO4) will react with all of the following in an exchange (metathesis) reaction except for which compound?
A) strontium bromide, SrBr2 B) potassium bromide, KBr
C) lead nitrate, Pb(NO3)2 D) barium nitrate, Ba(NO3)2
3. (3 pts) Potential energy in chemical systems arises primarily from __________.
A) movement of chemical species B) bond vibrations C) electrostatic interactions D) temperature
4. (3 pts) Identify the reducing agent in the chemical reaction below (as it proceeds in the direction shown):
Ag (s) + H2S (g) Ag2S (s) + H2 (g)
A) Ag B) H2
C) S2- D) H+
5. (3 pts) A 0.1 M solution of _____ will contain the lowest concentration of H+ ions.
A) HNO3 B) HCl C) HI D) HF
6. (3 pts) In which species does sulfur have the highest oxidation number?
A) S8 (elemental form of sulfur) B) SO2 C) H2SO3 D) K2SO4
-
4
7. (3 pts) A laser pointer used in a lecture hall emits light at 650 nm. What is the frequency of this radiation?
A) 4.6 x 1014 Hz B) 2.2 x 10-15 Hz C) 4.6 x 105 Hz D) 2.2 x 10-4 Hz
8. (3 pts) Which of these equations does not represent an oxidation-reduction reaction?
A) Zn (s) + 2HCl (aq) → H2 (g) + ZnCl2 (aq) B) 2H2O (l) → 2H2 (g) + O2 (g) C) Cu(NO3)2 (aq) + Zn (s) → Zn(NO3)2 (aq) + Cu (s) D) 2NaI (aq) + Pb(NO3)2 (aq) → PbI2 (s) + 2NaNO3 (aq)
9. (3 pts) The change in the internal energy of a system that absorbs 5.00 kJ of heat and that does 245 J of work on the surroundings is __________ J.
A) -4,755 B) -5,245 C) 5,245 D) 4,755
10. (3 pts) Hess’ Law allows for the enthalpy of a reaction to be calculated from the heats of formation of the reactants and products. This indirect calculation of ΔHrxn is possible because enthalpy is __________.
A) endothermic B) exothermic C) a state function D) energy
11. (3 pts) A 1.00 x 10-2 L volume of 0.100 M __________ will completely neutralize a 1.00 L solution of 2.00 mM NaOH.
A) H2SO4 B) H3PO4
C) CH3COOH D) HCl 12. (3 pts) Which of the following chemical species will not undergo an oxidation-reduction reaction with aluminum metal, Al (s)?
A) AuCl3 (aq) C) Pb (s) B) ZnBr2 (aq) D) AgNO3 (aq)
-
5
Section II: Calculation and long answer. Complete the following questions by showing your work and providing the answer in the box or line provided. Failure to show your work will result in no partial credit! 13. An infant Tylenol formulation (a flavored syrup solution called an oral suspension) contains 0.160 g acetaminophen in each 5.00 mL dose.
a. (3 pts) What volume (in mL) of this medication would an adult have to take in order to achieve the recommended adult dose of 0.500 g?
Answer: ___________________________
b. (3 pts) Imagine that you have been tasked by Johnson & Johnson to create an adult formulation of acetaminophen (M.W. = 151 g/mol). Assume that you are provided with a concentrated solution of acetaminophen to mix with the other ingredients in the syrup. Given that the concentration of this solution is 0.825 M, what volume of this solution must you dilute with syrup to 20.0 mL to achieve a final concentration of 0.165 M?
Answer: ___________________________
14. (3 pts) One type of sunburn occurs on exposure to UV light of wavelength in the vicinity of 325 nm. What is the energy of a photon of this wavelength?
Answer: ___________________________
15. (3 pts.) Name one kind of electromagnetic radiation that is lower in energy than visible light:
Answer: ___________________________ (There are multiple possible correct answers to question #15. Only one correct answer is required for full points.)
-
6
16. The following reaction was used to produce acetylene, an explosive gas, in the sock cannon demonstration in class.
CaC2 (s) + 2 H2O (l) Ca(OH)2 (s) + C2H2 (g) ∆Hº = −127.2 kJ
a. (3 pts) If 0.010 mol CaC2 were to be added to 1.00 L of water in a constant-pressure calorimeter, what temperature increase (∆T) is expected. Assume standard temperature and pressure. Use 4.18 J/g ºC as the specific heat of water.
Answer: ___________________________
b. (3 pts) Using the following standard heats of formation and the thermochemical
equation above, calculate the standard heat of formation of calcium carbide (CaC2).
Compound Standard heat of formation, ∆Hfº H2O (l) −285.83 kJ/mol Ca(OH)2 (s) −986.2 kJ/mol C2H2 (g) 226.8 kJ/mol
Answer: ___________________________
Extra credit (3 pts): Dynamite was invented by:______________________________. (first name) (last name)
-
7
Formulas and Equations
𝐸𝐸 = ℎ𝜈𝜈 𝜆𝜆 = 𝑐𝑐𝜈𝜈 𝐶𝐶𝑠𝑠 =
𝑞𝑞𝑚𝑚×∆𝑇𝑇
°F = 9
5(°C) + 32 °C = 5
9 (°F – 32) Kelvin = 0 °C + 273.15
Planck constant, h = 6.626 × 10-34 J-s Speed of light, c = 2.998 × 108 m/s Avogadro’s Number, NA = 6.022 × 1023 Density of water = 1.000 g/ml at 25 °C
1 in = 2.54 cm 100 cm =1 m 1,000 mm = 1 m 1 pm = 10-12 m 1 nm = 10-9 m 1 cm3 = 1 mL 1,000 mg = 1 g 1 kg = 2.20 lb
-
8
Periodic Table of t he Element s
103Lr
(260)
102No
(259)
101Md
(258)
100Fm
(257)
99Es
(252)
98Cf
(251)
97Bk
(247)
96Cm
(247)
95Am
(243)
94Pu
(244)
93Np
(237)
92U
238
91Pa
231
90Th
232
71Lu
175
70Yb
173
69Tm169
68Er
167
67Ho
165
66Dy
162
65Tb
159
64Gd
157
63Eu
152
62Sm150
61Pm
(145)
60Nd
144
59Pr
141
58Ce
140
8A18
7A17
6A16
5A15
4A14
3A13
Lant hanides
Act inides
109Mt
(266)
108Hs
(265)
107Bh
(262)
106Sg
(263)
105Db
(262)
104Rf
(261)
89Ac
227
88Ra
226
87Fr
(223)
83Bi
209
82Pb
207
81Tl
204
80Hg
201
79Au
197
78Pt
195
77Ir
192
76Os
190
75Re
186
74W
184
73Ta
181
72Hf
178
57La
139
56Ba
137
55Cs
133
51Sb
122
50Sn
119
49In
115
48Cd
112
47Ag
108
46Pd
106
45Rh
103
44Ru
101
43Tc
(98)
42Mo
95.9
41Nb
92.9
40Zr
91.2
39Y
88.9
38Sr
87.6
37Rb
85.586Rn
(222)
85At
(210)
84Po
(209)
52Te
128
53I
127
54Xe
131
36Kr
83.8
35Br
79.9
34Se
79.0
33As
74.9
32Ge
72.6
31Ga
69.7
30Zn
65.4
29Cu
63.5
28Ni
58.7
27Co
58.9
26Fe
55.8
25Mn
54.9
24Cr
52.0
23V
50.9
22Ti
47.9
21Sc
45.0
20Ca
40.1
19K
39.1
18Ar
39.9
17Cl
35.5
16S
32.1
15P
31.0
14Si
28.1
13Al
27.0
2He
4.0010Ne
20.2
9F
19.0
8O
16.0
7N
14.0
6C
12.0
5B
10.88B
2B12
1B111098
7B7
6B6
5B5
4B4
3B3
12Mg
24.3
11Na
23.0
4Be
9.01
3Li
6.94
2A2
1A1
1H
1.01
110Ds
(281)