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Oct 14, 2013
FORM A
--------------------------------------------------------------------------------1. A neutral atom has the following electron configuration. What
is the maximum number of covalent bonds this atom could form
with hydrogen atoms?
--------------------------------------------------------------------------------3. Which of the following is the most polar bond?
A. O!F
B. C!S
C. N!F
D. C!H
E. B!F
--------------------------------------------------------------------------------4. Which of following would have the highest dipole moment?
A. 1
B. 2
A. HF
C. 3
B. HCl
D. 4
C. HBr
E. 5
D. HI
--------------------------------------------------------------------------------2. How many valence electrons and lone pairs are in the structure
of the N2H4 molecule?
# lone pairs
A.
# valence
electrons
10
B.
14
2
C.
14
1
D.
10
2
E.
12
3
1
---------------------------------------------------------------------------------
E. All have the same dipole moment because they all
contain H
--------------------------------------------------------------------------------5. For which molecule is it not possible to draw a Lewis structure
which follows the octet rule?
A.
B.
C.
D.
E.
HF
CH2Cl2
N 2O 4
O3
PCl5
---------------------------------------------------------------------------------
--------------------------------------------------------------------------------6. Which of the following molecules has the longest C-C bond and
the weakest C-C bond?
C2F6
A.
B.
C.
D.
E.
longest bond
C2F2
C2F2
C2F4
C2F6
C2F6
C2F4
H
N
C2F2
weakest bond
C2F2
C2F6
C2F4
C2F6
C2F2
--------------------------------------------------------------------------------7. Which of the following contains both ionic and covalent bonds?
A.
B.
C.
D.
E.
--------------------------------------------------------------------------------9. What functional groups are present in the following aromatic
molecule?
ClF
SO2
NaCl
SO3
NaCN
i.
ii.
iii.
iv.
v.
A.
B.
C.
D.
E.
ketone
amine
alcohol
aldehyde
carboxylic acid
HO
O
OH
ii, iii, and v
i, ii, and iv
ii, iii, and iv
i, ii, and iii
ii, iv, and v
--------------------------------------------------------------------------------10. Which of the following is not an isomer of the others?
--------------------------------------------------------------------------------8. Which of the following formulas may represent a cycloalkane
with only one ring?
A. C2H2
B. C6H6
C. C6H14
D. C6H12
E. C5H12
---------------------------------------------------------------------------------
---------------------------------------------------------------------------------
--------------------------------------------------------------------------------11. What are the hybridizations of carbons labeled 1 and 2 in a
caffeine molecule (shown below)?
--------------------------------------------------------------------------------13. Identify the molecules that have a zero net dipole moment?
i.
ii.
iii.
CS2
CH2O
SeF2
A. i only
B. i and ii only
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120,
123,
120,
123,
12,
C. i and iii only
.0,
120,
123,
12,
120,
120,
--------------------------------------------------------------------------------12. Which of these molecules contains an odd number of electrons?
i.
ii.
iii.
A.
B.
C.
D.
E.
NO
ClO2
NO2
i only
ii only
iii only
i and iii
all three
---------------------------------------------------------------------------------
D. ii and iii only
E. i, ii, and iii
--------------------------------------------------------------------------------14. Which of the following molecules has a trigonal bipyramid
electron domain geometry?
A. NF4+
B. SeF42+
C. PF4+
D. SF4
E. XeF4
---------------------------------------------------------------------------------
--------------------------------------------------------------------------------15. C, N, and O atoms readily form multiple bonds with each other.
Which of these statements correctly explains why larger atoms in
period 3 do not readily form multiple bonds with each other?
--------------------------------------------------------------------------------17. Which of the following molecules are not linear?
i.
ii.
iii.
iv.
i.
The d-orbitals that become available in period 3 atoms such
as Si, P and S get in the way and block the formation of
multiple-bonds.
ii. The energy required to promote electrons to p-orbitals in Si,
P and S is so large than that the atomic orbitals cannot
hybridize.
iii. Unhybridized p-orbitals on Si, P, and S cannot form
multiple-bonds because the atoms are too large for the porbitals to overlap.
A.
B.
C.
D.
E.
i only
ii only
iii only
i and iii
all three
H 2O
CO2
C2H 2
C2H 4
A. i and ii only
B. ii and iii only
C. i and iii only
D. iii and iv only
E. i and iv only
--------------------------------------------------------------------------------18. How many " and ! bonds are in the molecule shown below?
--------------------------------------------------------------------------------16. What are the electron-domain and the molecular geometries of
SnCl3–?
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)$%4*+(5,2"$(6%&(5,
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?38<367@,
)7)$(87&$(5,
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---------------------------------------------------------------------------------
A.
B.
C.
D.
E.
"
18
8
6
18
8
!
2
2
2
3
1
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
19. Which of the following molecular ions has delocalized # bonds?
A. SO22–
--------------------------------------------------------------------------------21. Which one of the following organic molecules has the same
empirical formula as benzene?
B. CO32–
benzene
C. SiO44–
D. OH
–
E. PO33–
--------------------------------------------------------------------------------20. What is the % O by mass in the molecule below?
H
A.
B.
C.
H
D.
E.
--------------------------------------------------------------------------------22. An unknown sample weighs 2.1 g and contains 0.035 moles of
molecules. Identify the molecule.
A. 40.0%
A.
B.
C.
N
O
O
B. 41.8%
OH
C. 53.3 %
D. 58.2%
E. 60.0%
D.
E.
O
HO
---------------------------------------------------------------------------------
O
OH
---------------------------------------------------------------------------------
--------------------------------------------------------------------------------23. How many structural isomers can be drawn for C5H12?
A. 1
B. 2
C. 3
D. 4
E. 5
--------------------------------------------------------------------------------24. Which one of the following compounds can exist as cis/trans
isomers?
---------------------------------------------------------------------------------
--------------------------------------------------------------------------------25. Consider the neutral molecule with the molecular formula ClOF3.
Chlorine is the central atom and the remaining four atoms are
directly bonded to Cl. One of the F!Cl!F angles in this molecule
is 175° (i.e. approximately 180°). Based on this information,
select the incorrect statement from the choices below.
A. The molecular geometry of ClOF3 is best described as
approximately square planar.
B. ClOF3 has one non-bonding electron pair on Cl.
C. The three O!Cl!F angles in this molecule are approximately
90°, 90°, and 120°.
D. The electron domain geometry about the Cl atom is
trigonal bipyramid.
E. Every Lewis structure that can be drawn for ClOF3
violates the octet rule.
--------------------------------------------------------------------------------26. In the capsaicin molecule (the main capsaicinoid in chili peppers)
below, rank the angles indicated in order of increasing bond
angle. Hint: Lone pairs are not explicitly shown.
A.
B.
C.
D.
E.
1=3<2
1=2=3
2=3<1
1<3<2
1<2=3
---------------------------------------------------------------------------------
--------------------------------------------------------------------------------27. The energy of a covalent bond between two atoms is shown
below as a function of interatomic distance (r). Which of the
following statements are true?
--------------------------------------------------------------------------------28. Which of the following pairs are resonance structures?
i. Energy is released when this covalent bond is broken.
ii. The equilibrium bond length of this molecule is 180 pm.
iii. When the atoms are separated by 80 pm, the interaction
is repulsive.
A. i only
B. ii only
A. i only
C. iii only
B. ii only
D. i and iii
C. iii only
E. all three
D. i and iii
E. ii and iii
---------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------END OF EXAM
CHEMISTRY 110 EXAM 2
OCTOBER 14, 2013
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.
D
B
E
A
E
D
E
D
A
D
A
E
A
D
C
D
E
A
B
C
D
C
C
C
A
D
C
D