Chemistry 122
Exam 2
Spring 2008
May 22, 2008
Oregon State University
Dr. Richard Nafshun
Instructions: You should have with you several number two pencils, an eraser, your 3" x 5" note card, a calculator, and your University ID Card. If you have notes with you, place them in a sealed backpack and place the backpack OUT OF SIGHT or place the notes directly on the table at the front of the room.
Fill in the front page of the Scantron answer sheet with your last name, first name, middle initial, and student identification number. Leave the class section number and the test form number blank.
This exam consists of 25 multiple-choice questions. Each question has four points associated with it.
Select the best multiple-choice answer by filling in the corresponding circle on the rear page of the answer sheet. If you have any questions before the exam, please ask. If you have any questions during the exam, please ask the proctor. Open and start this exam when instructed. When finished, place your
Scantron form in the appropriate stack and present your University ID Card to the proctor. You may keep the exam packet, so please show your work and mark the answers you selected on it.
R = 0.0821 L•atm/mol•K
M = mol/L
ΠV = nRT ln[
A
A o
]
kt
760 mm Hg = 760 torr = 1 atm m = mol/kg
ΔT f
= imk f k f
(H
2
O) = 1.86 ºC/m
ΔT k b b
(H
= imk
2 b
O) = 0.512 ºC/m
SC: 2r = s BCC: 4r = s√3 FCC: 4r = s√2
1. Consider the phase diagrams below. Which diagram could correctly describe water?
2. Which of the following is false ?
(A) Quartz, graphite, and diamond are ionic compounds.
(B) Ethanol (CH
3
CH
2
OH) is a polar molecule which exhibits hydrogen bonding.
(C) Sodium oxide is an ionic compound.
(D) Sodium oxide melts at a higher temperature than ethanol.
(E) Network covalent compounds melt at higher temperatures than molecules.
3. Consider the phase diagram below for compound springfeverium. The temperature of condensation at 2 atm is:
(A) 0 ºC.
(B)
50 ºC
(C)
100 ºC
(D)
150 ºC
(E)
212 ºC
4. Which of the following compounds cannot undergo free radical polymerization?
(A) CH
2
ClCH
2
Cl
(B) CCl
2
CCl
2
(C) CH
2
CH
2
(D)
H
C C
H
H
(E) CF
2
CF
2
7.
6.
5. The reaction below will produce:
O O
|| ||
HOCH
2
OH + HOCCH
2
CH
2
CH
2
COH →
(A)
(D)
Quartz
(B) A network covalent compound
(C) An ionic compound
Soap
(E) A polymer
Sodium fluoride melts near 993 ºC. Sodium chloride melts near 804 ºC. The difference in melting points can be attributed to:
(A) Different intermolecular forces (dispersion, dipole-dipole, hydrogen bonding)
(B) Different ionic charges (+1, +2, +3, -1, -2, -3…)
(C) Different distances between nuclei (ionic size)
(D) Network covalent compounds
(E) One is a molecule (attractions by intermolecular forces), one is an ionic compound
(attractions by charges)
Ethane, CH
3
CH be attributed to:
3
, melts at -172 ºC. Li
2
O melts at 1570 ºC. The difference in melting points can
(A)
(B)
(C)
Different intermolecular forces (dispersion, dipole-dipole, hydrogen bonding)
Different ionic charges (+1, +2, +3, -1, -2, -3…)
Different distances between nuclei (ionic size)
(D) Network covalent compounds
(E) One is a molecule (attractions by intermolecular forces), one is an ionic compound
(attractions by charges)
8. Diethyl ether, CH
3
CH
2
OCH
2
CH
3
, boils at +34.6 ºC. 1-Butanol, CH
3
CH
2
CH
2
CH
2
OH boils at +117.3 °C. The difference in boiling points can be attributed to: diethyl ether 1-butanol,
9.
(A)
(B)
(C)
Different intermolecular forces (dispersion, dipole-dipole, hydrogen bonding)
Different ionic charges (+1, +2, +3, -1, -2, -3…)
Different distances between nuclei (ionic size)
(D) Network covalent compounds
(E) One is a molecule (attractions by intermolecular forces), one is an ionic compound
(attractions by charges)
Consider CH
3
CH
2
OH, CaO, CH
3
CH
3
, CaS, CH
Arranged in increasing melting point, these are:
3
OCH
3
, and Ar.
Lowest melting point Highest melting point
(A) CH
3
CH
2
OH < Ar < CH
3
CH
3
< CH
3
OCH
3
< CaO < CaS
(B) Ar < CH
3
CH
3
< CH
3
OCH
3
< CH
3
CH
2
OH < CaS < CaO
(C) Ar < CH
3
OCH
3
< CH
3
CH
3
< CH
3
CH
2
OH < CaO < CaS
(D) Ar < CH
3
CH
3
< CH
3
OCH
3
< CH
3
CH
2
OH < CaO < CaS
(E) Ar < CH
3
CH
3
< CH
3
CH
2
OH < CH
3
OCH
3
< CaO < CaS
10. i for AlCl
3
is:
(A)
(B)
(C)
0
1
2
(D) 3
(E) 4
11. Which of the following molecules will not form hydrogen bonds?
O
(A) H
3
C CH
2
C OH (B) HF
O H
(C)
H
3
C CH
2
C CH
3
(D) H
3
C CH
2
N CH
12. The intermolecular forces that are most significant in accounting for the high boiling point of liquid water relative to other substances of similar molecular weight is/are the:
(A)
(B)
Dispersion forces
Dipole-dipole interactions
(C) Hydrogen bonding
(D) Network covalent forces
(E) Ionic charges
13. The equivalent number of atoms in the SC unit cell is:
(A) 1
(B) 2
(C) 3
(D) 4
(E) 6
3
14. The structure below [from a Course Worksheet ] represents:
(A) An SC unit cell
(B) A BCC unit cell
(C) An FCC unit cell
(D) A stem cell
(E) A jail cell
15. The cubic form for the fictitious element itsalmostsummerium is FCC. The atomic radius is
155.9 pm and the molar mass is 320.6 g/mol. The density of itsalmostsummerium is:
[1 m = 1 x 10
12
pm 1 m = 100 cm]
(A) 1.55 g/cm 3
(B) 24.8 g/cm
3
(C) 397 g/cm
3
(D) 99.3 g/cm 3
(E) 49.7 g/cm
3
16. The freezing point of 2.45 m MgCl
2
(aq) is:
(A) - 1.86
C
(B) - 2.45
C
(C) - 4.56
C
(D) - 13.7
C
(E) - 9.11
C
17. Which of the following sets of compounds are expected to be soluble in water?
(A) CH
4
, CO
2
, CF
4
(B) NaCl, CH
4
, CH
3
OCH
3
(C) NaCl, CH
3
CH
2
OH, NH
3
(D) NaCl, CCl
4
, C
4
H
10
18. A student dissolves 5.66 g of an unknown protein in 1.75 L of water at 300 K. She measures the osmotic pressure to be 9.355 x 10
-4
atm. What is the molar mass of the protein?
(A) 8.52 x 10
4
g/mol
(B) 6.65 x 10
4
g/mol
(C) 6.65 x 10
-4
g/mol
(D) 1.17 x 10
4
g/mol
(E) 2.08 x 10
4
g/mol
19. Generally, which of the following generally does not increase the reaction rate?
(A)
(B)
Increase the temperature
Add a catalyst
(C) Increase the activation energy
(D) Increase the reactant concentrations
20. The half-life is:
(A) The amount of time required for half the sample to decay
(B) 0.500 years
(C) The amount of time required for the entire sample to decay
(D) 42 years
(E)
A
A o
21. A student ( ) obtains a 1.000 gram sample of
131m Xe will remain after 24.0 days?
131m
Xe (t
1/2
= 12.0 days). How many grams of
(A)
(B)
(C)
(D)
(E)
1.00 gram
0.500 grams
0.250 grams
0.125 grams
0.000 grams
22. A student ( ) obtains a 1.255 gram sample of
14
C (t
1/2
= 5730 years). How long will it take so that only 0.167 grams of
14
C remain?
(A)
(B)
5730 years
16,669 years
(C)
(D)
(E)
57,300 years
28,659 years
34,824 years
23. The half-life of DDT is 8 years. In 1940 the concentration of DDT was measured to be one gallon per acre in a plot. What was the concentration of DDT in this plot in 1956?
(A)
(B)
8 gal/acre
1 gal/acre
(C) 4 gal/acre
(D) 0.5 gal/acre
(E) 0.25 gal/acre
24. The following are initial rate data for:
Experiment Initial [A]
1
2
3
0.10
0.20
0.10
A + 2 B
Initial [B]
0.10
0.10
0.20
C + 2 D
Initial Rate
0.222
0.444
0.888
(A)
(B)
(C)
(D)
(E)
The rate law is Rate = k[A]
The rate law is Rate = k[A]
The rate law is Rate = k[A]
The rate law is Rate = k[A]
The rate law is Rate = k[A]
1
[B]
2
[B]
2 [B]
0
[B]
1
[B]
2
1
0
1
0
25. The Chemistry 122 final exam is Monday, June 9, 2008 at 7:30am (Good Morning!) Yes, this is near my usual bedtime. After the chemistry final I will be...
(A) Drinking heavily (root beer, of course)
(B) Working my parents for my share of our stimulus check
(C) Spending an enormous amount at time at the theater watching summer movies
(D) Preparing for my other seven final exams
(E) ( Censored )
[Any response will receive full credit; even no response]