CHM 220 General Review for Covalent Bonding and Associated Topics
Electronegativity
1. Arrange the following elements in order of increasing electronegativity (least electronegative to most
electronegative).
S
Br
F
Na
(A)
Na<F<S<Br
(B)
Br<Na<S<F
(C)
Na<S<Br<F
(D)
Na<Br<F<S
2. Arrange the following elements in order of decreasing electronegativity.
O
N
C
F
S
(A)
F>O>N>C>S
(B)
F>N>O>S>C
(C)
O>S>F>N>C
(D)
F>O>N>S>C
3. Arrange the following elements in order of increasing electronegativity.
N
S
Li
Si
C
(A)
S<Si<Li<C<N
(B)
Li<Si<C<S<N
(C)
Si<C<Li<N<S
(D)
Li<C<N<S<Si
4. Which of the following molecules has the greatest difference in electronegativity between the two different
elements?
(A)
CO
(B)
CS2
(C)
H2O
(D)
CN-
5. Arrange the following compounds in the order of increasing ionic character of the indicated bonds.
H3C Cl
H3C SH
H3C OH
H3C NH 2
2
3
4
1
(A)
1<2<4<3
(B)
2<4<1<3
(C)
4<3<1<2
(D)
3<4<1<2
6. Which of the following compounds are nonpolar?
H2O
1
CO2
2
NH3
3
(A)
2&3
(B)
2&4
(C)
1&3
(D)
3&4
BF3
4
CHCl3
5
Lewis Structures
7. Which of the following Lewis structures are correct?
H
H N H
H O H O
Cl
H
1
H O H
H
Cl
Cl C Cl
Cl
3
4
2
(A)
1, 2, 3
(B)
1, 3, 4
(C)
2, 3, 4
(D)
1, 2, 4
8. Which of the following Lewis structures are incorrect?
O O O
N N
Cl Cl
1
2
3
H
H C O H
H 4
(A)
1, 2, 3
(B)
1, 4, 5
(C)
2, 3, 4
(D)
3, 4, 5
H H
H C N H
H 5
9. Which of the following Lewis structures are correct?
H H
C C C
H
H
1
H O O H
H
H Si H
H
2
3
H
H
H B H
H
4
(A)
2, 3, 4
(B)
1, 3, 4, 5
(C)
1, 2, 6
(D)
3, 4, 5
H
H N O H
H
6
S C S
5
10. What is the correct Lewis structure for formaldehyde?
O
H
Structure A
C
O
O
H C O H
H
(A)
H
(B)
C
H
H
(C)
C
H
(D)
11. Which of the following are examples of electron configurations with completed outer shells?
Sp
1
(A)
1, 3, 4
(C)
2, 6
1s
2
2
1s2s
3
2
2
2
1s 2s 2p
4
(B)
2, 4
(D)
2
2
1s 2s 3s
5
2
2
2
6
1s 2s 2p
6
1, 4, 6
12. Which of the following Lewis structures are correct?
H O
O
N
1
O
Cl H
Na
2
O H
3
H
O
N
4
(A)
1, 2, 3
(B)
1, 3, 4
(C)
2, 4, 5
(D)
2, 3, 5
H
H
H
H C C N
H
5
Formal Charge
13. Carbon has a formal charge in which of the following compounds and ions?
(A)
(C)
CO2
CS2
-2
(B)
CO3
(D)
+
CF3
14. Carbon has a formal charge in which of the following ions?
+
(B)
[HCO]
-
(D)
[CH3OH2]
(A)
[(CH3)4N]
(C)
[CH3CO2]
+
+
15. Carbon has a formal charge in which of the following?
-
(A)
HCO3-
(B)
CH3CO2
(C)
CH3OH
(D)
LiCH3
16. Nitrogen has a negative charge in which of the following compounds?
(A)
NaNH2
(B)
N2
(C)
NH4Cl
(D)
HCN
Bond Angles and Geometry
17. Which of the following molecules have bond angles of about 109.5 degrees?
CS2
1
-
BCl3
2
-
AlCl4
3
+
NH2
4
(A)
1, 2, 4
(B)
3, 4, 5
(C)
2, 3, 4
(D)
1, 3, 5
NH4
5
18. What is the bond angle for the indicated atom in the following molecules?
H2CO
H2C CH2
O
H3C C CH3
H3CHC NOH
3
4
2
1
o
o
(A)
109.5
(B)
180
(C)
o
(D)
120
90
o
19. Which of the following molecules have a tetrahedral shape?
BH3
1
H2O
2
H3O
3
+
(A)
1, 3, 5
(B)
1, 2, 4, 5
(C)
3, 4, 5
(D)
2, 3, 5
+
20. What is the molecular geometry (shape) of NO2 ?
(A)
tetrahedral
(B)
linear
(C)
planar
(D)
trigonal
NH4Cl
4
CCl4
5
-
21 What is the geometry (shape) of CH3 ?
(A)
tetrahedral
(B)
linear
(C)
planar
(D)
trigonal
Functional Groups
22 Which of the following matches of names and molecules is correct?
1. CH3CO2CH3
2. H2CO
3. CH3CHO
4. CH3OH
A. ester
B. alcohol
C. aldehyde
D. carboxylic acid
(A)
A&3, C&2
(B)
B&2, D&1
(C)
A&1, B&4
(D)
C&3, D&4
23 Which of the following matches of names and molecules is correct?
A. alcohol
B. aldehyde
C. ketone
D. carboxylic acid
1. HCOOH
2. (CH3)3COH
3. CH3OCH3
4. CH3COCH3
(A)
A&2, C&4
(B)
B&2, D&1
(C)
A&3, B&4
(D)
C&3, D&4
24 Which of the following is an acid derivative?
O
(B) is an acid derivative
O
(B)
(A)
OCH 3
O
(C) CH3OCH 3
O
(D)
H
25 Which functional groups are in the following molecule?
1. carboxylic acid
2. alcohol
3. aldehyde
NH2
4. ester
5. ketone
HOH 2C C COOH
COCH 3
(A)
1, 2, 3
(B)
2, 3, 4
(C)
1, 3, 5
(D)
1, 2, 5
26 Which functional groups are in the following molecule (Penicillin G)?
COOH
O
1. carboxylic acid
2. alcohol
3. aldehyde
4. ether
5. ketone
O
O
(A)
1, 4
(B)
2, 3, 5
(C)
3, 4, 5
(D)
1, 4, 5
N
N
H
S
27. Which functional groups are in the following molecule (NutrasweetTM)?
1. carboxylic acid
2. alcohol
3. aldehyde
4. ether
5. ester
6. ketone
O
NH 3
HO
H
N
O
OCH 3
O
(A)
1, 5
(B)
1, 4
(C)
2, 4
(D)
3, 4
Constitutional Isomers
28. How many constitutional isomers are there for an alcohol having the molecular formula C4H9OH?
(A)
2
(B)
3
(C)
4
(D)
5
29. How many different aldehydes or ketones can there be for compounds with the molecular formula C3H6O?
(A)
1
(B)
2
(C)
3
(D)
4
30. How many constitutional isomers are possible for a compound having the molecular formula C4H10O?
(A)
4
(B)
5
(C)
6
(D)
7
31. Which of the following do not belong in the group of constitutional isomers?
(A)
(B)
(C)
(D)
32. Which of the following do not belong in the group of constitutional isomers of C5H10?
1
2
3
4
(A)
1, 3, 4
(B)
2, 4, 5
(C)
1, 2, 4
(D)
2, 3, 5
5
Resonance
33. Which of the following are contributing resonance structures?
O
1.
O
4.
CH2
O
2.
OH
OH2
OH
3.
5.
(A)
1, 2
(B)
3, 4
(C)
2, 5
(D)
1, 3
CH2
34. Which of the following are not contributing resonance structures?
1. HN C O
HO C N
N C O
O C N
2.
3.
4.
(A)
1, 2
(B)
2, 4
(C)
1, 3
(D)
3, 4
O
OH
O
O
35. Which of the following are contributing resonance structures?
O
O
1.
4.
OH
NH 2
NH 2
O
2.
O
O
5.
3.
(A)
1, 4, 5
(B)
2, 3, 5
(C)
2, 3, 4
(D)
1, 2, 3
36. Which of the following pairs are contributing resonance structures?
A. H2C CHCH 2
1. HC CHCH 3
B. HCl
C. H2C CHCH 3
2. H Cl
3. H3CHC CH2
D. HC CHCH 3
4. HC CHCH 3
E. CH3CH2OH 2
5. CH3CH2
(A)
A and 1, B and 2
(B)
C and 3, D and 4
(C)
A and 4, D and 1
(D)
B and 2, E and 5
OH 2
37. Contributing resonance structures can have different energies, and the structure that has the lowest energy is
the most important. In the following pairs of resonance structures, which structure makes the greater
contribution? (Can you explain why and put in the arrows that show the electron movements?)
(CH3)2C OH
(CH3)2C OH
1
2
O
O
NH 2
3
NH 2
4
O
O
5
6
(A)
1, 3, 5
(B)
2, 4, 6
(C)
2, 3, 6
(D)
1, 3, 6
38. In each pair of contributing structures, which structure makes the greater contribution? (Can you explain why
and put in the arrows that show the electron movements?)
H3C C N O
1
H3C C N O
2
H2N C N
3
H2C OH
5
H2C OH
H2N C N
4
6
(A)
1, 3, 4
(B)
2, 4, 6
(C)
1, 4, 5
(D)
2, 3, 6
39. Which of the following ions are stabilized by resonance?
O
1
3
2
(A)
1, 2
(B)
1, 3
(C)
2, 4
(D)
3, 4
4
Orbitals and Hybridization
40. What is the order of increasing energy for the following orbitals?
3
1. sp
2
2. sp
3. sp
(A)
5, 3, 2, 1, 4
(B)
4, 5, 3, 2, 1
(C)
1, 2, 3, 4, 5
(D)
4, 3, 2, 1, 5
4 .s
5. p
41. Which are the correct orbital hybridizations for the carbon atoms in the following structures?
H2C O
H2C CH2
sp
2
sp
1
HC N
CH3
2
3
(A)
1, 2, 3
(B)
sp
4
2, 3, 4
(C)
2, 4, 5
(D)
1, 4, 5
sp
3
O C O
sp
5
42. What are the correct orbital descriptions for the indicated atoms?
BH3
CH 4 BeH2
F2
A
B
D
C
1.
2.
3.
4.
sp3
sp2
sp
p
(A)
A and 1, C and 2
(B)
B and 1, D and 4
(C)
B and 1, C and 3
(D)
B and 2, D and 3
43. What are the correct orbital hybridizations for carbon in the following?
A. CH4
B. CH3
C. CH3
2
1. sp
3
3. sp
2. sp
(A)
A and 3, B and 2
(B)
B and 3, C and 2
(C)
B and 2, C and 1
(D)
A and 1, B and 3
44. When forming molecular orbitals from the following atomic orbitals, what is the order of decreasing strength
for the resulting bond (strongest first)?
3
1. sp
2
2. sp
3. sp
(A)
1, 2, 3, 4
(B)
4, 3, 2, 1
(C)
3, 2, 1, 4
(D)
4, 3, 1, 2
4. p
45. What is the order of increasing bond length (shortest and strongest first) derived from the following molecule
orbitals?
3
3
1. sp -sp
2
2
2. sp -sp
3. sp-sp
(A)
4, 3, 2, 1
(B)
3, 2, 1, 4
(C)
2, 3, 1, 4
(D)
1, 2, 3, 4
46. Which carbon-hydrogen bond is the strongest?
H
D
H
H C C C
A
(A)
(C)
A
C
(B)
(D)
H
B
D
H
H
B
C
4. p-p
47. Arrange the following in decreasing order of s character for the indicated bonds.
HO
H
H2N
1
H
H3C
2
H
F
3
(A)
3, 2, 1, 4
(B)
4, 3, 2, 1
(C)
1, 2, 3, 4
(D)
4, 1, 2, 3
H
4
+
48. What is the hybridization of the carbon-hydrogen bond in the methyl cation ( CH3)?
3
2
(A)
sp
(B)
sp
(C)
sp
(D)
p
-
49. What is the hybridization of the boron in BH4 ?
3
2
(A)
sp
(B)
sp
(C)
sp
(D)
p
50. What orbitals are overlapping to form the nitrogen-boron bond in H3N-BF3?
3
(A)
p-sp
(C)
sp -sp
3
3
3
2
(B)
sp -sp
(D)
p-p
51. Which compound has the most s character in the carbon-hydrogen bond?
A
B
C
(A)
A
(B)
B
(C)
C
(D)
D
D