CHEMISTRY 110 EXAM 2
Oct. 15, 2012
FORM A
--------------------------------------------------------------------------------------------1. Which of the following is an incorrect formula for a neutral compound
made from the given ions?
!
"#$%&'!
#'%&'!
(&)*+,#!
--------------------------------------------------------------------------------------------3. Which of the following molecules are ionic?
i.
ii.
iii.
CO2
KCl
Na2CO3
A. i only
B. ii only
-.!! aluminum
oxide
Al2O3
C. i and iii
/.!! magnesium
nitride
Mg3N2
D. ii and iii
0.!! calcium
oxide
CaO
E. all three
1.!! ammonium
chloride
NH4Cl
2.!! sodium
phosphate
Na(PO4)2
--------------------------------------------------------------------------------------------2. How many molecules are in 5.23 g of glucose (C6H12O6)?
--------------------------------------------------------------------------------------------4. Which of the following best describes propane, butane, and octane?
A. The molecules contain only C, O and H.
B. The molecules contain only C and H and are isomers of each other.
A. 9.03 ! 10
22
C. The molecules contain only C and H and at least 1 double bond.
B. 3.05 ! 10
23
D. The molecules contain only C and H and only single bonds.
C. 2.25 ! 10
24
E. The molecules share no common characteristics.
D. 1.75 ! 10
22
E. 4.20 ! 1023
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--------------------------------------------------------------------------------------5. Which of the following best describes the electron domain geometry of
bromine pentafluoride?
A. trigonal bipyramidal
B. seesaw-shaped
--------------------------------------------------------------------------------------------8. Mass analysis of an unknown compound found it contained 5.532%
hydrogen, 79.095% carbon and 15.373% nitrogen by weight. Mass
spectrometry determined the molecular weight of the compound to be
182.2 g/mol. What is the molecular formula of the compound?
A. C6H5N
C. tetrahedral
B. C5H3N2
D. square pyramidal
C. C10H6N4
E. octahedral
D. C11H8N3
--------------------------------------------------------------------------------------------6. Which of the following will have less lattice energy than NaCl?
E. C12H10N2
A. LiF
B. LiCl
C. NaF
--------------------------------------------------------------------------------------------9. Which of the following is correct regarding structural isomers?
D. KBr
E. MgS
i.
--------------------------------------------------------------------------------------------7. What is the empirical formula for the compound drawn below?
O
A. C3H4O
O
H
iii. They have the same molar mass.
A. i only
B. C9H12O3
C. C8H9O3
They have different molecular formulas.
ii. They have the same connectivity of the atoms.
O
B. ii only
C. iii only
D. CHO
D. i and iii
E. C9H11O3
E. all of these are true.
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--------------------------------------------------------------------------------------------10. An unknown compound is analyzed and found to contain C, H, and Br.
Upon further analysis, it is also found to be 45.9% carbon and 3.21%
hydrogen. Which of the following could be the unknown compound?
--------------------------------------------------------------------------------------------11. Which of the followings pairs are isomers?
--------------------------------------------------------------------------------------------12. Which one of the following molecules does NOT have a geometric
isomer?
--------------------------------------------------------------------------------------------13. Which functional group is NOT present in the compound shown below.
I.
A. II only
B. II and III
C. I, II and IV
OH
II.
OH
D. I, II, III and IV
E. II, III and IV
III.
A. amide
Cl
Cl
B. carboxylic acid
C. ester
IV.
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D. amine
E. alcohol
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--------------------------------------------------------------------------------------------14. Which of the following molecules will adopt a trigonal planar geometry?
I.
II.
III.
BF3
ClF3
NH3
--------------------------------------------------------------------------------------------16. Which figure best illustrates the hybridization of the central atom; sulfur
in sulfur dioxide (SO2) and carbon in carbon disulfide (CS2)?
A. I only
B. II only
i.
C. III only
ii.
SO2
CS2
D. I and II only
A.
iii
i
E. I, II, and III
B.
ii
ii
C.
i
iii
D.
ii
i
E.
i
i
--------------------------------------------------------------------------------------------15. Which orbital hybridization(s) of the C atoms is (are) contained in the
molecule shown below?
i.
ii.
iii.
sp
sp2
sp3
--------------------------------------------------------------------------------------------17. Which of the following gives the correct number of ! and " bonds in the
molecule shown?
A. i and ii only
A.
!
14
"
5
B. ii and iii only
B.
15
5
C. i and iii only
C.
15
6
D. iii only
D.
20
6
E. all three
E.
25
6
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iii.
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--------------------------------------------------------------------------------------------18. What kind of intermolecular interactions are important in pure liquid
acetic acid (CH3COOH)?
i.
ii.
iii.
dipole-dipole
hydrogen bonding
dispersion force
--------------------------------------------------------------------------------------------20. Use your knowledge of VSEPR theory to rank the indicated bond angles
in order of decreasing angle.
I.
O
OH
C
H
A. i and ii only
O
CH2
B. iii only
II.
C. ii only
D. ii and iii only
A. II = I > III
E. all three
B. I > II = III
H
C
III.
H
C. II > III > I
--------------------------------------------------------------------------------------------19. Rank the following molecules in order of decreasing molecular polarity
D. III > II > I
E. I > III > II
--------------------------------------------------------------------------------------------21. Which of the following molecules will experience dipole-dipole
interactions?
A. I > III > II
I. SF4
B. I > II > III
A. I only
C. II > III > I
B. II and IV
D. III > I > II
C. I, III, IV
E. II > I > III
D. I and III
II. CH4
III. SeCl2
IV. PF5
E. All of the above
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--------------------------------------------------------------------------------------------22. A compound containing only P-Cl bonds was analyzed and found to
contain by mass 22.6% phosphorus. What is the hybridization of the
phosphorus atom?
--------------------------------------------------------------------------------------------24. Why does the boiling point of straight-chain hydrocarbons increase with
the length of the carbon chain?
Boiling Points of Alkanes
A. sp3d2
200
B. sp3d
150
100
Boiling Point
C. sp
3
D. sp2
E. sp
--------------------------------------------------------------------------------------------23. Which of the following molecules has delocalized ! bonds?
50
0
-50
-100
-150
-200
0
I.
II.
III.
ozone (O3)
hydrogen cyanide (HCN)
acetylene (C2H2)
2
4
6
8
10
Number of Carbons
A. Hydrogen bonding increases with chain length.
A. I only
B. Polarity decreases with chain length.
B. II only
C. Intermolecular forces decrease with chain length.
C. III only
D. The number of isomers decreases with chain length.
D. I and II
E. London dispersion forces increase with chain length.
E. I and III
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--------------------------------------------------------------------------------------------25. Calculate the % H for the compound shown below
O
Br
H
--------------------------------------------------------------------------------------------27. Which one of the following correctly depicts the H-bonding between the
two molecules? In these figures, hydrogen bonds are indicated with the
hatched lines (
).
H
O
A.
C
H
H
O
C
C
H
H
H
C
H
H
A. 0.48%
B. 0.52%
C. 7.3%
H
B.
D. 46.3%
H
O
C
H
O
C
H
C
H
H
E. 38.6 %
C
H
H
H
--------------------------------------------------------------------------------------------26. A student has 50 g of each of these molecules in a separate vial. Which
sample has the greatest number of oxygen atoms?
C.
H
H
C
H
O
C
C
O
C
H
H
H
H
H
O
H
H
C
D.
H
H
C
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H
C
C
H
H
H
H
E.
H
C
H
C
H
O
C
C
O
H
H
O
H
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--------------------------------------------------------------------------------------------28. Put these in order of increasing melting points.
Ar
A.
B.
C.
D.
E.
LiF C6H14
Ar < C6H14 < LiF
Ar < LiF < C6H14
LiF < C6H14 < Ar
C6H14 < Ar < LiF
LiF < Ar < C6H14
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END OF EXAM
CHEMISTRY 110 EXAM 2
OCTOBER 15, 2012
Answer Key
FORM A
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
E
D
D
D
E
D
A
E
C
A
B
D
E
A
B
D
E
E
B
E
D
C
A
E
C
E
B
A