Chapter 1 - Homework - Chemistry Laboratory | Trường Đại học Quốc tế, Đại học Quốc gia Thành phố HCM

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29 15 lượt tải Tải xuống
Chia sẻ Báo cáo tài liệu

Môn: Chemistry Laboratory (CH012IU)

Trường: Trường Đại học Quốc tế, Đại học Quốc gia Thành phố Hồ Chí Minh

Thông tin:

15 trang 4 tháng trước

Tác giả:

Profile Mai Nguyệt
Page 1
Chapter 1
1.
Which is the most electronegative atom in the compound below?
N
H
Br
O
H
A) Carbon B) Nitrogen C) Oxygen D) Bromine
Ans: C
2.
Which of the following correctly describes the electrons of a carbon atom in its ground
state?
A) 3 electrons; 3 electrons s p
B) 2 1 electrons; 4 2 electrons s p
C) 2 1 electrons; 2 2 electrons; 2 2 electrons s s p
D) 2 1 electrons; 2 2 electrons; 4 2 electrons s s p
E) None of these choices is correct.
Ans: C
3.
Which of the following statements correctly describes the typical bonding of carbon,
nitrogen, and oxygen in organic molecules?
A) Carbon participates in 4 covalent bonds, oxygen participates in 2 covalent bonds
and nitrogen participates in 5 covalent bonds.
B) Carbon participates in 3 covalent bonds, oxygen participates in 2 covalent bonds
and nitrogen participates in 5 covalent bonds.
C) Carbon participates in 4 covalent bonds, oxygen participates in 3 covalent bonds
and nitrogen participates in 3 covalent bonds.
D) Carbon participates in 3 covalent bonds, oxygen participates in 3 covalent bonds
and nitrogen participates in 5 covalent bonds.
E) Carbon participates in 4 covalent bonds, oxygen participates in 2 covalent bonds
and nitrogen participates in 3 covalent bonds.
Ans: E
4.
Which is an acceptable Lewis structure for the anion (CHnot
2
NCO)
–
?
a. b.
C
N
C
O
H
H
C N C O
H
H
C
N
C
O
H
H
d.
C
N
C
O
H
H
c.
A) a B) b C) c D) d
Ans: C
Page 2
5.
Which of the following is (are) valid Lewis structure(s) for the anion (HCONCH
3
)
–
?
H
C
N
C
H
O
H H
H
C
N
C
H
O
H H
b.
c.
d. a and b
e. a, b, and
c
H N H
C
H H
O
a.
A) a B) b C) c D) d E) e
Ans: D
6.
Which of the following is (are) valid Lewis structure(s) for the anion (CH
2
NO
2
)
–
?
Assume the atoms are arranged as drawn.
a.
b. c. d. a and b e. a, b, and
c
C N
O
OH
H
C N
O
OH
H
C N
O
OH
H
A) a B) b C) c D) d E) e
Ans: E
7.
Which is the appropriate conversion of CH
3
CHClCH
2
CH(CH
3
)
2
to a skeletal formula?
a.
b.
c.
d. e.
C
C
l
C
l
Cl
C
A) a B) b C) c D) d E) e
Ans: B
8.
Convert the following compound from a condensed formula to a skeletal formula:
CH
3
CH
2
C(CH
3
)
2
CH
2
CH(CH
2
CH
3
)CH
2
CH(CH
3
)
2.
a. b. c.
d.
e. None of the choices is correct.
A) a B) b C) c D) d E) e
Ans: D
Page 3
9.
What is the condensed formula of the compound below?
Br
B
r
a. CH
3
CH
2
CH(CH
3
)CH
2
CH(CH
3
)CHBr
2
b. CH
3
CH
2
CH
2
(CH
3
)CH
2
CH(CH
3
)CHBr
2
c. CH
3
CH
2
CH(CH
3
)CH(CH
3
)CH
2
CHBr
2
A) a B) b C) c
Ans: A
10.
Convert the following skeletal formula to a condensed formula.
a. CH
3
CH
2
CH(CH
3
)
2
CH(CH
2
CH
3
)CH(CH
3
)
2
b. CH
3
CH
2
CH(CH
3
)CH(CH
2
CH
3
)CH(CH
3
)
2
c. CH
3
CH(CH
3
)CH(CH
2
CH
3
)CH(CH
3
)
2
A) a B) b C) c
Ans: B
11.
Which of the following is a valid Lewis structure of CHnot
3
NO
2
?
H N
O
H
H
O
H N
O
H
H
O
H N
O
H
H
O
2
a.
b.
c. d.
H N
O
H
H
O
A) a B) b C) c D) d
Ans: B
Page 4
12.
Which is a valid resonance structure for the anion below? not
a. b.
c.
H
2
C CH
3
O
H
2
C
CH
3
O
H
2
C CH
3
O
e. All are valid resonance structures.d.
H
2
C
CH
3
O
H
2
C CH
3
O
A) a B) b C) c D) d E) e
Ans: C
13.
How are the molecules in the following pair related?
H
3
C
O
CH
2
H
3
C
O
C
H
2
and
A) They are constitutional isomers. C) They represent the same structure.
B) They are resonance structures.
Ans: B
14.
How are the molecules in the following pair related?
and H
3
C C C
H
A) They are constitutional isomers. C) Neither of the choices is correct.
B) They are resonance structures.
Ans: A
15.
How are the molecules in the following pair related?
and
O Cl
O
C
l
A) They are constitutional isomers. C) Neither of the choices is correct.
B) They are resonance structures.
Ans: A
16.
How are the molecules in the following pair related?
and
A) They are constitutional isomers. C) They are unrelated molecules.
B) They are resonance structures.
Ans: C
Page 5
17.
How are the molecules in the following pair related?
and
H
3
C
N
O
H
3
C
N
O
O
O
A) They are constitutional isomers. C) Neither of the choices is correct.
B) They are resonance structures.
Ans: B
18.
How are the molecules in the following pair related?
and
A) They are constitutional isomers. C) Neither of the choices is correct.
B) They are resonance structures.
Ans: A
19.
How are the molecules in the following pair related?
and
A) They are constitutional isomers. C) Neither of the choices is correct.
B) They are resonance structures.
Ans: B
20.
How are the molecules in the following pair related?
H
3
C CH
3
H
3
C N
H
OHNH
and
A) They are constitutional isomers. C) They are unrelated molecules.
B) They are resonance structures.
Ans: C
21.
How are the molecules in the following pair related?
H
3
C CH
3
O
and
O
H
A) They are constitutional isomers. C) Neither of the choices is correct.
B) They are resonance structures.
Ans: A
Page 6
22.
Which is the most accurate representation of the resonance hybrid for the resonance
structures shown below?
O
O
O
a. b.
c.
d.
e. None of the choices is correct.
O
O
O
O
δ
−
δ
−
δ
−
δ
−
δ
−
δ
−
δ
−
δ
−
δ
−
δ
−
δ
−
δ
−
A) a B) b C) c D) d E) e
Ans: B
23.
Which of the following pairs of compounds are resonance structures?
b.
H H
3
C CH
3 3
C CH
2
O OH
CH
3
CH
3
and
and
and
a.
c.
A) a B) b C) c
Ans: B
24.
Which of the following structures are resonance structures of each other?
b.a.
c.
A) a and b
B) b and c
C) a and c
D) All are resonance structures.
E) None of these are resonance structures.
Ans: A
Page 7
25.
What is the hybridization for each of the indicated atoms in the following compound?
H
2
C
N
CH
3
a
b
c
A)
a
- sp
2
;
b
- sp
2
;
c
- sp
2
C)
a
- ; sp
b
- sp
2
;
c
- sp
3
B)
a
- sp
2
;
b
- sp
3
;
c
- sp
3
D)
a
- sp
2
;
b
- sp
2
;
c
- sp
3
Ans: D
26.
Indicate the hybridization of the carbon ion in each compound below.
C
H
3
C
H
3
a.
b.
A)
a
- sp
2
;
b
- sp
2
B)
a
- sp
2
;
b
- sp
3
C)
a
- sp
3
;
b
- sp
3
D)
a
- sp
3
;
b
- sp
2
Ans: D
27.
Consider the organic molecule drawn below. Describe which orbitals are used to form
the C=O bond. Since there are two bonds, you must identify two different sets of
orbitals.
O
O
H
A) C
sp
2
– O
sp
2
and C
s
– O
p
D) C
sp
3
– O
sp
2
and C
p
– O
p
B) C
sp
– O
sp
and C
p
– O
p
E) C
sp
2
– O
sp
2
and C
2p
– O
2p
C) C
sp
2
– O
sp
2
and C
s
– O
s
Ans: E
28.
Which of the following compounds has a labeled carbon atom that is sp
2
hybridized?
H
2
C C CH
2
H
3
C CH
3
H
3
C CH
3
NH
CH
3
a.
c.b.
d. Compounds b and c e. and all have a, b c sp
3
hybridized carbon.
A) a B) b C) c D) d E) e
Ans: D
Page 8
29.
Which of the following compounds contains a labeled atom that is hybridized? (All sp
nonbonded electron pairs have been drawn in.)
C O
HC N O C
a.
c. d. a and bb.
e. a, b and
c
H
A) a B) b C) c D) d E) e
Ans: D
30.
Which of the compounds drawn below contains an sp
2
hybridized carbon atom? Select
any and all structures that apply.
H
2
C O
a
.
C
O
2
c. CH
3
+
d
.
C
H
3
O
H
b.
A) a only B) b only C) d only D) a and b E) b and c
Ans: E
31.
Which of the labeled carbon atoms is (are) sp
2
hybridized?
b.
CH
3
+
O
CH
2
C CH
2
a. c. d. a and b e. a, b and
c
A) a B) b C) c D) d E) e
Ans: D
32.
Which statement best describes the orbital hybridization used to form bonds in the
cation below?
CH
2
C N
A)
The
σ
bond between the two carbon atoms is formed between two sp
2
hybridized
atoms.
B)
The
σ
bond between the C and N is formed between an sp
2
hybridized C and an
sp hybridized N.
C)
The
σ
bond between the two carbons is formed between one sp
3
hybridized C and
one hybridized C. sp
D) The lone pair of electrons on N is in an hybridized orbital. sp
E) None of the statements is correct.
Ans: D
Page 9
33.
Indicate the formal charge on the B, O, and F atoms in the following compound.
F
B
O
Cl Cl
A) B: +1; O: +1; F: 0 D) B: –1; O: +1; F: 0
B) B: –1; O: –1; F: 0 E) None of the choices is correct.
C) B: +1; O: –1; F: 0
Ans: D
34.
In the following compound, indicate the formal charge on all atoms except hydrogen.
H
C
N
O
A) Carbon +1; Oxygen +1; Nitrogen –2 D) Carbon +1; Oxygen –1; Nitrogen –1
B) Carbon –1; Oxygen +1; Nitrogen –2 E) None of the choices is correct.
C) Carbon +1; Oxygen –1; Nitrogen –2
Ans: C
35.
In the following compound, indicate the formal charge on all atoms except hydrogen,
from left to right.
C N C O
H
H
H
A) Carbon 0; Nitrogen –1; Carbon +1; Oxygen 0
B) Carbon –0; Nitrogen –1; Carbon 0; Oxygen –1
C) Carbon 0; Nitrogen –1; Carbon 0; Oxygen –1
D) Carbon 0; Nitrogen +1; Carbon 0; Oxygen –1
E) None of the choices is correct.
Ans: D
36.
Which of the following compounds has a labeled atom with a +1 formal charge? (All
nonbonded electron pairs have been drawn in.)
a.
c.
H
2
C
N
N
H
C
CH
2
H
C
CH
2
H C H
H
N
O
H
H
H
b.
d. e.
A) a B) b C) c D) d E) e
Ans: C
Page 10
37.
Which of the following species has a labeled atom with a +1 formal charge? (All
nonbonded electron pairs have been drawn in.)
a.
c.
H
3
C C CH
3
b.
d.
e.H
2
C O
N
H
H
N
H
H
H
A) a B) b C) c D) d E) e
Ans: A
38.
Which of the following species contains a carbon atom with a +1 formal charge? (All
nonbonded electron pairs have been drawn in.)
H
C
C
H
H
H
H
H
C
C
H
H
C CH
H
C N
CH
3
H
CH
3
H
C
C
H
H
H
H
a.
b. c. d.
e.
A) a B) b C) c D) d E) e
Ans: A
39.
Which of the following species contains a carbon atom with a –1 formal charge? (All
nonbonded electron pairs have been drawn in.)
H C C H
H
C
C
H
H
C HH
H
C
H
H
CH
2
C CH
2
a.
b.
c. d. e.
A) a B) b C) c D) d E) e
Ans: B
40.
Which of the following species contains an O atom with a +1 formal charge? (All
nonbonded electron pairs have been drawn in.)
a.
b. c.
d. e.
O
OH
O O
O
N
O
A) a B) b C) c D) d E) e
Ans: B
41.
Which of the following species contains a carbon atom with a +1 formal charge? (All
nonbonded electrons and electron pairs have been drawn in.)
a.
b.
c.
d.
e.C C
H
H
C N
CH
3
H
CH
3
H
C
C
CH
3
H
H
O
H
CH
2
H
C
C
H
H
A) a B) b C) c D) d E) e
Ans: D
Page 11
42.
Which of the following species has (have) a trigonal planar structure with 120° bond
angles around the labeled carbon atom?
a.
b.
c. d. b and c e. a, b and
c
H
2
C C CH
2
H
3
C CH
3
N
H
H
3
C CH
3
C
H
3
A) a B) b C) c D) d E) e
Ans: D
43.
Which of the following molecules has (have) a trigonal planar geometry?
a.
b.
c. d. a and c e. None of the choices are corre
c
O
O N
H
A) a B) b C) c D) d E) e
Ans: A
44.
Which of the following compounds possess(es) a nitrogen with tetrahedral geometry?
A) CH
3
C N:
B) NH
2
–
C) NH
4
+
D) CH
3
C N: and NH
2
–
are both tetrahedral.
E) NH
2
–
and NH
4
+
are both tetrahedral.
Ans: E
45.
Which of the following molecules is (are) polar?
a
.
C
H
3
C
l
b
.
C
H
2
C
l
2
c
.
C
C
l
4
A) a B) b C) c D) a and b E) b and c
Ans: D
46.
Which of the following statements is (are) correct?
A) Ethane has sp
3
carbon atoms and the geometry around each carbon is trigonal
planar.
B) Ethane has sp
3
carbon atoms and the geometry around each carbon is tetrahedral.
C) Ethane has sp
2
carbon atoms and the geometry around each carbon is tetrahedral.
D) Ethane has sp
2
carbon atoms and the geometry around each carbon is trigonal
planar.
E) None of the statements are correct.
Ans: B
Page 12
47.
Which of the following statements is (are) correct?
A) The carbon–carbon distance in acetylene is longer than in ethylene.
B) The carbon–hydrogen bond in acetylene is weaker than the carbon–hydrogen
bond in ethane.
C) The carbon–carbon distance in acetylene is shorter than in ethane.
D) The statements (The carbon–carbon distance in acetylene is longer than in
ethylene) and (The carbon hydrogen bond in acetylene is weaker than the carbon
hydrogen bond in ethane) are correct.
E) The statements (The carbon hydrogen bond in acetylene is weaker than the carbon
hydrogen bond in ethane) and (The carbon–carbon distance in acetylene is shorter
than in ethane) are correct.
Ans: C
48.
How many hydrogens are directly bonded to each of the indicated carbon atoms?
C
a
C
b
C
c
A) C
a
1; C
b
3; C
c
2 D) C
a
1; C
b
3; C
c
3
B) C
a
2; C
b
3; C
c
2 E) None of the choices is correct.
C) C
a
1; C
b
2; C
c
2
Ans: A
49.
Of the molecules listed, which does have a dipole moment? not
A) HCl B) NCl
3
C) CO D) BF
3
E) All molecules have a dipole
moment.
Ans: D
50.
For the elements Rb, F, and O, the order of increasing electronegativity is:
A) Rb < F < O D) F < Rb < O
B) Rb < O < F E) The order cannot be determined.
C) O < F < Rb
Ans: B
51.
Which of the following Lewis dot structure(s) below bear(s) a positive charge?
a.
b.
c. d.
e.
Be
H
H
B
H
H
H H
N
H
H H
N
H
H
H H
O
A) a B) b C) c D) c and d E) d and e
Ans: E
Page 13
52.
Which of the following species has (have) a trigonal planar structure?
a. b. c. d.
e.
CH
3
CH
3
NH
3
BF
3
OH
3
A) a, b, and c D) b, d, and e
B) b and d E) All of the choices are correct.
C) d
Ans: B
53.
What is the molecular shape of methyl anion?
CH
3
A) Octahedral D) Trigonal pyramidal
B) Tetrahedral E) Linear
C) Trigonal planar
Ans: D
Challenge Questions
54.
Enalapril
is currently in clinical trials for congestive heart failure, and its structure is
given below. What is the correct molecular formula for this interesting
antihypertensive agent?
HN
N
O
O
O
O
H
O
E
n
a
l
a
p
r
i
l
a. C
20
H
28
N
2
O
5
b. C
18
H
26
N
2
O
5
e. C
18
H
25
N
2
O
5
d. C
20
H
26
N
2
O
5
c. C
16
H
24
N
2
O
5
A) a B) b C) c D) d E) e
Ans: A
Page 14
55.
The following compound is a synthetic intermediate in the production of
lactacystin
.
Identify the orbital hybridization and geometry of the atoms next to the three arrows.
N
O
O
Si
CN
O
a
b
c
A)
a
– sp
3
;
b
– sp
2
;
c
– sp
3
D)
a
– sp
3
;
b
– sp
2
;
c
– sp
B)
a
– sp
2
;
b
– ; sp
c
– sp
3
E) None of the choices is correct.
C)
a
– sp
2
;
b
– sp
3
;
c
– sp
2
Ans: D
56.
The following scheme represents an S
N
1 mechanism for the conversion of alkyl halide
“a” to ether “ .” Determine the correct structure for intermediate “ ” based on the b X
curved arrow formulism shown.
I
OH
H
H
OH OH OH
+ I
X
a
b
O
O
H
O
H
H
OH
H
a
.
b
.
c
.
d
.
e
.
A) a B) b C) c D) d E) e
Ans: C
Page 15
57.
With reference to compound
X
drawn below, label each compound as an isomer, a
resonance structure or neither.
a
.
b
.
c
.
d
.
N
O
H
X
N
O
H
N
O
H
N
O
NH
2
H
O
A)
a.
resonance structure;
b.
isomer;
c.
neither;
d.
isomer
B)
a.
isomer;
b.
resonance structure;
c.
isomer;
d.
neither
C)
a.
isomer;
b.
neither;
c.
isomer;
d.
resonance structure
D)
a.
resonance structure;
b.
isomer;
c.
resonance structure;
d.
isomer
E) None of the choices are correct.
Ans: D
Use the following to answer questions 58-60:
Answer the following questions about , a commonly used dental anesthetic. lidocaine
N
N
O
a
H
cLidocaine
58.
What orbitals are used to form the bond indicated by
a
?
A) Csp
2
―Csp
2
B) Csp
3
―Csp
2
C) Csp
2
― ―Csp D) Csp Csp
2
E)
Csp
3
―Csp
Ans: B
59.
How many carbon atoms have sp
2
hybridization?
A) 7 B) 5 C) 6 D) 10 E) 8
Ans: A
60.
Predict the geometry around the oxygen atom indicated by arrow
c
.
A) Linear D) Trigonal planar
B) Tetrahedral E) Square planar
C) Trigonal bipyrimidal
Ans: D
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Chapter 1
1. Which is the most electronegative atom in the compound below? OH Br N H
A) Carbon B) Nitrogen C) Oxygen D) Bromine Ans: C
2. Which of the following correctly describes the electrons of a carbon atom in its ground state? A)
3 s electrons; 3 p electrons B)
2 1s electrons; 4 2p electrons C)
2 1s electrons; 2 2s electrons; 2 2p electrons D)
2 1s electrons; 2 2s electrons; 4 2p electrons E)
None of these choices is correct. Ans: C
3. Which of the following statements correctly describes the typical bonding of carbon,
nitrogen, and oxygen in organic molecules? A)
Carbon participates in 4 covalent bonds, oxygen participates in 2 covalent bonds
and nitrogen participates in 5 covalent bonds. B)
Carbon participates in 3 covalent bonds, oxygen participates in 2 covalent bonds
and nitrogen participates in 5 covalent bonds. C)
Carbon participates in 4 covalent bonds, oxygen participates in 3 covalent bonds
and nitrogen participates in 3 covalent bonds. D)
Carbon participates in 3 covalent bonds, oxygen participates in 3 covalent bonds
and nitrogen participates in 5 covalent bonds. E)
Carbon participates in 4 covalent bonds, oxygen participates in 2 covalent bonds
and nitrogen participates in 3 covalent bonds. Ans: E
4. Which is not an acceptable Lewis structure for the anion (CH2NCO)–? H a. b. H N H N H N C N C O C C c. d. C C C C O O O H H H H A) a B) b C) c D) d Ans: C Page 1
5. Which of the following is (are) valid Lewis structure(s) for the anion (HCONCH3) –? O H H O H H O H H a. C C b. C C c.
d. a and b
e. a, b, and c C H N H H N H H N H A) a B) b C) c D) d E) e Ans: D
6. Which of the following is (are) valid Lewis structure(s) for the anion (CH2NO2)–?
Assume the atoms are arranged as drawn. H O H O H O a. C N b. C N c. C N
d. a and b
e. a, b, and c H O H O H O A) a B) b C) c D) d E) e Ans: E
7. Which is the appropriate conversion of CH3CHClCH2CH(CH3)2 to a skeletal formula? Cl a. b. c. d. e. Cl C Cl Cl A) a B) b C) c D) d E) e Ans: B
8. Convert the following compound from a condensed formula to a skeletal formula:
CH3CH2C(CH3)2CH2CH(CH2CH3)CH2CH(CH3)2. a. b. c. d.
e. None of the choices is correct. A) a B) b C) c D) d E) e Ans: D Page 2
9. What is the condensed formula of the compound below? Br Br
a. CH3CH2CH(CH3)CH2CH(CH3)CHBr2
b. CH3CH2CH2(CH3)CH2CH(CH3)CHBr2
c. CH3CH2CH(CH3)CH(CH3)CH2CHBr2 A) a B) b C) c Ans: A
10. Convert the following skeletal formula to a condensed formula.
a. CH3CH2CH(CH3) 2CH(CH2CH3)CH(CH3 )2
b. CH3CH2CH(CH3)CH(CH2CH3)CH(CH3)2
c. CH3CH(CH3)CH(CH2CH3)CH(CH 3)2 A) a B) b C) c Ans: B
11. Which of the following is not a valid Lewis structure of CH3NO2? H H H H H H H H a. O b. c. O O d. 2 O H N H N H N H N O O O O A) a B) b C) c D) d Ans: B Page 3
12. Which is not a valid resonance structure for the anion below? O H2C CH3 O O O a. b. c. H2C CH3 H H 2 C CH3 2C CH3 O d.
e. All are valid resonance structures. H2C CH3 A) a B) b C) c D) d E) e Ans: C
13. How are the molecules in the following pair related? O H and O 3C CH2 H C 3 CH2 A)
They are constitutional isomers. C)
They represent the same structure. B)
They are resonance structures. Ans: B
14. How are the molecules in the following pair related? and H3C C CH A)
They are constitutional isomers. C)
Neither of the choices is correct. B)
They are resonance structures. Ans: A
15. How are the molecules in the following pair related? O O Cl and Cl A)
They are constitutional isomers. C)
Neither of the choices is correct. B)
They are resonance structures. Ans: A
16. How are the molecules in the following pair related? and A)
They are constitutional isomers. C) They are unrelated molecules. B)
They are resonance structures. Ans: C Page 4
17. How are the molecules in the following pair related? O O and N N H O 3C O H3C A)
They are constitutional isomers. C)
Neither of the choices is correct. B)
They are resonance structures. Ans: B
18. How are the molecules in the following pair related? and A)
They are constitutional isomers. C)
Neither of the choices is correct. B)
They are resonance structures. Ans: A
19. How are the molecules in the following pair related? and A)
They are constitutional isomers. C)
Neither of the choices is correct. B)
They are resonance structures. Ans: B
20. How are the molecules in the following pair related? NH OH and H3C CH3 H3C NH A)
They are constitutional isomers. C) They are unrelated molecules. B)
They are resonance structures. Ans: C
21. How are the molecules in the following pair related? O OH and H3C CH3 A)
They are constitutional isomers. C)
Neither of the choices is correct. B)
They are resonance structures. Ans: A Page 5
22. Which is the most accurate representation of the resonance hybrid for the resonance structures shown below? O O O δ− δ− δ− δ− O O O O a. δ− b. c. δ− δ− δ− d. δ− δ− δ− δ−
e. None of the choices is correct. A) a B) b C) c D) d E) e Ans: B
23. Which of the following pairs of compounds are resonance structures? O OH b. and and a. H H 3C CH3 3C CH2 CH CH 3 3 c. and A) a B) b C) c Ans: B
24. Which of the following structures are resonance structures of each other? a. b. c. A) a and b B) b and c C) a and c D) All are resonance structures. E)
None of these are resonance structures. Ans: A Page 6
25. What is the hybridization for each of the indicated atoms in the following compound? N H2C CH3 b a c A)
a - sp2; b - sp 2; c - sp2 C)
a - sp; b - sp2; c - sp3 B)
a - sp2; b - sp 3; c - sp3 D)
a - sp2; b - sp2; c - sp3 Ans: D
26. Indicate the hybridization of the carbon ion in each compound below. C H3 C H3 a. b.
A) a - sp2; b - sp2 B) a - sp2; b - sp3 C) a - sp3; b - sp3 D) a - sp3; b - sp2 Ans: D
27. Consider the organic molecule drawn below. Describe which orbitals are used to form
the C=O bond. Since there are two bonds, you must identify two different sets of orbitals. O O H A) C 2 2 3 2
sp – Osp and C s– Op D)
Csp – Osp and Cp – Op B) C 2 2
sp – Osp and Cp – Op E)
Csp – Osp and C2p – O2p C) C 2 2
sp – Osp and C s – Os Ans: E
28. Which of the following compounds has a labeled carbon atom that is sp2 hybridized? NH CH3 a. H2 C C CH2 b. c. H H 3C CH3 3C CH3
d. Compounds b and c
e. a, b and c all have sp 3 hybridized carbon. A) a B) b C) c D) d E) e Ans: D Page 7
29. Which of the following compounds contains a labeled atom that is sp hybridized? (All
nonbonded electron pairs have been drawn in.) a. C O b. HC N c. O C H d. a and b e. a, b and c A) a B) b C) c D) d E) e Ans: D
30. Which of the compounds drawn below contains an sp2 hybridized carbon atom? Select
any and all structures that apply. a. CO + 2 b. H d. CH 2 C O c. CH3 3 OH
A) a only B) b only C) d only D) a and b E) b and c Ans: E
31. Which of the labeled carbon atoms is (are) sp 2 hybridized? O a. b. CH + 3 c. H C 2C CH2 d. a and b e. a, b and c A) a B) b C) c D) d E) e Ans: D
32. Which statement best describes the orbital hybridization used to form bonds in the cation below? H C 2C N A)
The σ bond between the two carbon atoms is formed between two sp2 hybridized atoms. B)
The σ bond between the C and N is formed between an sp2 hybridized C and an sp hybridized N. C)
The σ bond between the two carbons is formed between one sp3 hybridized C and one sp hybridized C. D)
The lone pair of electrons on N is in an sp hybridized orbital. E)
None of the statements is correct. Ans: D Page 8
33. Indicate the formal charge on the B, O, and F atoms in the following compound. Cl Cl B F O A) B: +1; O: +1; F: 0 D) B: –1; O: +1; F: 0 B) B: –1; O: –1; F: 0 E)
None of the choices is correct. C) B: +1; O: –1; F: 0 Ans: D
34. In the following compound, indicate the formal charge on all atoms except hydrogen. O C H N A)
Carbon +1; Oxygen +1; Nitrogen –2 D)
Carbon +1; Oxygen –1; Nitrogen –1 B)
Carbon –1; Oxygen +1; Nitrogen –2 E)
None of the choices is correct. C)
Carbon +1; Oxygen –1; Nitrogen –2 Ans: C
35. In the following compound, indicate the formal charge on all atoms except hydrogen, from left to right. H H C N C O H A)
Carbon 0; Nitrogen –1; Carbon +1; Oxygen 0 B)
Carbon –0; Nitrogen –1; Carbon 0; Oxygen –1 C)
Carbon 0; Nitrogen –1; Carbon 0; Oxygen –1 D)
Carbon 0; Nitrogen +1; Carbon 0; Oxygen –1 E)
None of the choices is correct. Ans: D
36. Which of the following compounds has a labeled atom with a +1 formal charge? (All
nonbonded electron pairs have been drawn in.) H N C C N H a. H N 2C b. H c. CH H CH d. H C H e. H O 2 2 H A) a B) b C) c D) d E) e Ans: C Page 9
37. Which of the following species has a labeled atom with a +1 formal charge? (All
nonbonded electron pairs have been drawn in.) H H H a. b. c. H H2C O d. H3C C CH3 e. N N H A) a B) b C) c D) d E) e Ans: A
38. Which of the following species contains a carbon atom with a +1 formal charge? (All
nonbonded electron pairs have been drawn in.) H H CH H 3 a. C H b. C H c. H C C d. C N e. C H H C H C H C H CH H H H 3 H H A) a B) b C) c D) d E) e Ans: A
39. Which of the following species contains a carbon atom with a –1 formal charge? (All
nonbonded electron pairs have been drawn in.) H H a. H C C H b. C H c. H C H d. C e. H C H C H H 2C CH2 A) a B) b C) c D) d E) e Ans: B
40. Which of the following species contains an O atom with a +1 formal charge? (All
nonbonded electron pairs have been drawn in.) OH O a. O b. c. d. e. N O O O A) a B) b C) c D) d E) e Ans: B
41. Which of the following species contains a carbon atom with a +1 formal charge? (All
nonbonded electrons and electron pairs have been drawn in.) H CH3 H CH2 a. H C C b. C N c. C CH3 d. e. C H H CH H C H C 3 H OH H A) a B) b C) c D) d E) e Ans: D Page 10
42. Which of the following species has (have) a trigonal planar structure with 120° bond
angles around the labeled carbon atom? NH CH3 a. H b. c. H
d. b and c e. a, b and c 2C C CH2 H3C CH3 3C CH3 A) a B) b C) c D) d E) e Ans: D
43. Which of the following molecules has (have) a trigonal planar geometry? O H a. b. O c. N d. a and c
e. None of the choices are correc A) a B) b C) c D) d E) e Ans: A
44. Which of the following compounds possess(es) a nitrogen with tetrahedral geometry? A) CH3C N: B) NH – 2 C) NH + 4 D) CH – 3C
N: and NH2 are both tetrahedral. E) NH – +
2 and NH4 are both tetrahedral. Ans: E
45. Which of the following molecules is (are) polar? a. C H3Cl b. CH2Cl2 c. C Cl4
A) a B) b C) c D) a and b E) b and c Ans: D
46. Which of the following statements is (are) correct? A)
Ethane has sp3 carbon atoms and the geometry around each carbon is trigonal planar. B)
Ethane has sp3 carbon atoms and the geometry around each carbon is tetrahedral. C)
Ethane has sp2 carbon atoms and the geometry around each carbon is tetrahedral. D)
Ethane has sp2 carbon atoms and the geometry around each carbon is trigonal planar. E)
None of the statements are correct. Ans: B Page 11
47. Which of the following statements is (are) correct? A)
The carbon–carbon distance in acetylene is longer than in ethylene. B)
The carbon–hydrogen bond in acetylene is weaker than the carbon–hydrogen bond in ethane. C)
The carbon–carbon distance in acetylene is shorter than in ethane. D)
The statements (The carbon–carbon distance in acetylene is longer than in
ethylene) and (The carbon hydrogen bond in acetylene is weaker than the carbon
hydrogen bond in ethane) are correct. E)
The statements (The carbon hydrogen bond in acetylene is weaker than the carbon
hydrogen bond in ethane) and (The carbon–carbon distance in acetylene is shorter than in ethane) are correct. Ans: C
48. How many hydrogens are directly bonded to each of the indicated carbon atoms? Cc Ca Cb A) Ca 1; Cb 3; Cc 2 D) Ca 1; Cb 3; Cc 3 B) Ca 2; Cb 3; Cc 2 E)
None of the choices is correct. C) Ca 1; Cb 2; Cc 2 Ans: A
49. Of the molecules listed, which does not have a dipole moment?
A) HCl B) NCl3 C) CO D) BF 3 E) All molecules have a dipole moment. Ans: D
50. For the elements Rb, F, and O, the order of increasing electronegativity is: A) Rb < F < O D) F < Rb < O B) Rb < O < F E)
The order cannot be determined. C) O < F < Rb Ans: B
51. Which of the following Lewis dot structure(s) below bear(s) a positive charge? H H H H H a. Be b. H B H c. d. H N H e. N O H H H H
A) a B) b C) c D) c and d E) d and e Ans: E Page 12
52. Which of the following species has (have) a trigonal planar structure? a. CH b. c. d. 3 CH 3 NH e. 3 BF3 OH3 A) a, b, and c D) b, d, and e B) b and d E)
All of the choices are correct. C) d Ans: B
53. What is the molecular shape of methyl anion? CH3 A) Octahedral D) Trigonal pyramidal B) Tetrahedral E) Linear C) Trigonal planar Ans: D Challenge Questions
54. Enalapril is currently in clinical trials for congestive heart failure, and its structure is
given below. What is the correct molecular formula for this interesting antihypertensive agent? OH O O N a. C20H 28N2O5 d. C20H26N2O5 HN b. C O 18H26N 2O5 e. C18H25N2O5 O c. C16H 24N2O5 Enalapri l A) a B) b C) c D) d E) e Ans: A Page 13
55. The following compound is a synthetic intermediate in the production of lactacystin.
Identify the orbital hybridization and geometry of the atoms next to the three arrows. a O O N Si CN O b c A)
a – sp3; b – sp 2; c – sp3 D)
a – sp3; b – sp2; c – sp B)
a – sp2; b – sp; c – sp3 E)
None of the choices is correct. C)
a – sp2; b – sp 3; c – sp2 Ans: D
56. The following scheme represents an SN1 mechanism for the conversion of alkyl halide
“a” to ether “b.” Determine the correct structure for intermediate “X” based on the curved arrow formulism shown. I H O H OH OH OH OH + I X a b H H OH H O O H a. b. c. d. e. A) a B) b C) c D) d E) e Ans: C Page 14
57. With reference to compound X drawn below, label each compound as an isomer, a
resonance structure or neither. O O H O O N N N N NH H H O H 2 X a. b. c. d. A)
a. resonance structure; b. isomer; c. neither; d. isomer B)
a. isomer; b. resonance structure; c. isomer; d. neither C)
a. isomer; b. neither; c. isomer; d. resonance structure D)
a. resonance structure; b. isomer; c. resonance structure; d. isomer E)
None of the choices are correct. Ans: D
Use the following to answer questions 58-60:
Answer the following questions about lidocaine, a commonly used dental anesthetic. H a N N O Lidocaine c
58. What orbitals are used to form the bond indicated by a? 2 2 3 2 2 2
A) Csp ―Csp B) Csp ―Csp C) Csp ―Csp D) Csp―Csp E) Csp3―Csp Ans: B 2
59. How many carbon atoms have sp hybridization? A) 7 B) 5 C) 6 D) 10 E) 8 Ans: A
60. Predict the geometry around the oxygen atom indicated by arrow c. A) Linear D) Trigonal planar B) Tetrahedral E) Square planar C) Trigonal bipyrimidal Ans: D Page 15