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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.

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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.

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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

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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)

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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.)

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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)

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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

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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)