Chem 2300
Exam 1
September 27, 2013
Name:
(Please print)
(First)
(Last)
Last 4 digits of A
Number
Score
I. Multiple Choice
(
/90
/30)
II
/10
Total score
/100
Note: Periodic table and pKa Values are on page 13.
1
I. Multiple choice questions. (3 points each). Please put your answers on Scantron sheet. Your
score will be graded based only on your answers from Scantron sheet.
1. Which is the electronic configuration that describes Mg?
(a)
(b)
(c)
(d)
(e)
1S2, 2S2
1S2, 2S2, 2P6
1S2, 2S2, 2P6, 3S2
1S2, 2S2, 2P6, 3S2, 3P6
None of the above
2. What is the definition of isotope?
(a)
(b)
(c)
(d)
(e)
Atoms that have the same number of proton but different number of electron.
Atoms that have the same number of proton but different number of neutron.
Atoms that have the same number of neutron but different number of proton.
Atoms that have the same number of neutron but different number of electron.
None of the above
3. In the figure on the right, which represent the correct tendency of electronegativity?
(a)
(b)
(c)
(d)
(e)
I. C > O
II. O > C
III. F > O
IV. Li > C
V. N > C
I, IV, VI
II, III, V
I, III, V
II, IV, V
None of the above
4. What is the skeletal structure for the following compound?
CH3CH2CH2CH2CH2N(CH3)2
2
5. What are the correct Lewis structures for the following compounds?
(a)
(b)
(c)
(d)
(e)
I, III, V, VI, VII, IX
I, III, IV, V, VII, IX
I, II, IV, VI, VII, IX
I, III, V, VII, IX
None of the above
6. Acetaminophen, the active ingredient in Tylenol, is a commonly used drug for reducing pain,
reducing fever, and relieving the symptoms of allergies, cold, cough, and flu. Using the VSEPR
model, predict which atoms have sp2 hybridization. (Note: lone-pair electrons are not shown)
(a)
(b)
(c)
(d)
(e)
Those pointed by arrows “a”, “c” and “e”.
Those pointed by arrows “a”, “c”, “d” and “e”.
Those pointed by arrows “b”, “d” and “e”.
Those pointed by arrows “b”, “d” and “f”.
None of the above
3
7. Amoxicillin is a moderate-spectrum, bacteriolytic, β-lactam antibiotic used to treat bacterial
infections caused by susceptible microorganisms. Using the VSEPR model, predict which atoms
have sp3 hybridization. (Note: lone-pair electrons are not shown)
(a)
(b)
(c)
(d)
(e)
Those pointed by arrows “a”, “c” and “e”.
Those pointed by arrows “a”, “c”, “d” and “e”.
Those pointed by arrows “b”, “c” and “e”.
Those pointed by arrows “b”, “d” and “f”.
None of the above
8. Organic compounds that have more polarized functional group, such as C=O, OH or NH2,
tend to interact more strongly with water and become more soluble in water. Which of the
following vitamin would be the most soluble in water (water soluble)?
4
9. What will be the dominant structure of alanine (an amino acid) at pH = 7.3 (physiological
pH)?
(a)
(b)
(c)
(d)
(e)
I,
II
III
IV
None of the above
10. What is the bond angle for each H-C-C and each C-C-C of tert-butyl cation, respectively?
(a)
(b)
(c)
(d)
(e)
120º and 120º
109.5º and 120º
120º and 109.5º
180º and 120º
None of the above
11. What could be the dominant forms of compounds found in the following acid/base reaction?
CH3NH2
+
I
(a)
(b)
(c)
(d)
(e)
CH3CO2H
II
+
CH3NH3
III
CH3CO2
IV
I, II
III, IV
I, III
II, IV
None of the above
12. What could be the dominant forms of compounds found in the following acid/base reaction?
NH3
I
(a)
(b)
(c)
(d)
(e)
+
CH3CH2OH
II
NH4
III
I, II
III, IV
I, III
II, IV
None of the above
5
+
CH3CH2O
IV
13. Which compound(s) below Lewis acid?
(a)
(b)
(c)
(d)
(e)
I, II, III
I, III, IV
I, II, IV
III, IV, V
None of the above
14. Which compound(s) of the following can function as nucleophile?
(a)
(b)
(c)
(d)
(e)
I, II, III
IV, V, VI
II, IV, V
III, IV, VI
None of the above
15. Arrange the following compounds in order of their acidity (from the most acidic to the least).
I
CH3CH2OH
(a)
(b)
(c)
(d)
(e)
II
CF3CO2H
I>III>II>IV
II>III>I>IV
II>III>IV>I
III>II>IV>I
None of the above
16. What is the IUPAC name for the following compound?
(a)
(b)
(c)
(d)
(e)
4-methyl-5-ethylheptane
2-propyl-3-ethylpentane
3-methyl-2-ethylheptane
3-ethyl-4-methylheptane
None of the above
6
III
CCl3CO2H
IV
CH3CO2H
17. What is the IUPAC name for the following compound?
(a)
(b)
(c)
(d)
(e)
2,4-dimethyl-1-isopropylcyclopentane
1,3-dimethyl-4-isopropylcyclopentane
1-isopropyl-2,4-dimethylcyclopentane
1-isopropyl-3,5-dimethylcyclopentane
None of the above
18. What is the systematic name for the following compound?
(a)
(b)
(c)
(d)
(e)
4-cyclopropyloctane
5-cyclopropyloctane
octylcyclopropane
1-cyclopropyl-1-propylpentane
None of the above
19. What is the systematic name for the following compound?
(a)
(b)
(c)
(d)
(e)
1,2,2-trimethylcyclohexane
1,1,2-trimethylcyclohexane
1,1,6-trimethylcyclohexane
1,6,6-trimethylcyclohexane
None of the above
20. How many 1º carbons are there in the following molecules?
(a)
(b)
(c)
(d)
(e)
2
3
4
5
None of the above
CH3
CH2
CH
H3C
CH
CH2
CH3
CH3
21. How many tertiary (3°) carbons does cholesterol have? (Note: sp2 hybridized carbon and
carbon with heteroatom attached (ex. O, N, and halogens) cannot be classified as 1°, 2°, 3° or 4°)
(a)
(b)
(c)
(d)
(e)
6
7
8
9
10
cholesterol
7
22. Sodium benzoate is a widely used food preservative. Which of the following can be used to
most effectively provide sodium benzoate when mixed with benzoic acid?
(a)
(b)
(c)
(d)
(e)
NaCl
NaHSO4
NaHCO3
NaH2PO4
None of the above
23. Which compounds belong to primary (1º) alkyl alcohols?
OH
CH2OH
CH3
CH3 C
CH3
I
CH2
CH2
II
OH
III
CH3
CH3 C
H
C
CH2
CH3
OH
IV
HO
VI
V
HO
O
IX
VIII
VII
(a)
(b)
(c)
(d)
(e)
OH
OH
CH3
I, III, V
II, III, V
III, VII, VIII
II, III, VII
None of the above
8
24. What is the systematic name for the following compound?
(a)
(b)
(c)
(d)
(e)
4-ethyl-5-chlorooctane
5-chloro-4-ethyloctane
4-chloro-5-ethyloctane
5-ethyl-4-chlorooctane
None of the above
25. Which of the following is not a structure isomer when compared to other molecules?
26. Which of the following compounds when exist in pure form can have hydrogen bond?
O
O
O
OH
OH
I
(a)
(b)
(c)
(d)
(e)
II
III
IV
I, II, III
II, III
I, IV
I, III, IV
None of the above
9
V
27. Which of the following compounds belong to 2º amine?
CH3
NH
NH2
NH2
NH
IV
III
II
I
N
CH3CH2CH2NH2
CH3CH2CH2CH2CH2N(CH3)2
V
N
VI
VIII
VII
NH2
NH2
NH2
NH2
IX
NH2
X
(a)
(b)
(c)
(d)
(e)
XI
XII
I, II, III
II, III
II, IX, XI
I, IV, V, XII
None of the above
28. Which of the following molecules is the least stable?
CH3
CH3
CH3
I
Cl
(a)
(b)
(c)
(d)
(e)
Cl
II
CH3
Cl
III
I
II
III
IV
None of the above
10
IV
Cl
29. Which of the following molecules represents cis isomer?
CH3
CH3
CH3
CH3
I
II
CH3
(a)
(b)
(c)
(d)
(e)
CH3
III
CH3
IV
CH3
I, II
II, III
III, IV
II, III, IV
None of the above
30. What is the order of stability for the following conformational isomers of n-butane (most to
least)?
CH3
H
H
HH
CH3
H
H
CH3
H
H
H
H3C
H
II
I
(a)
(b)
(c)
(d)
(e)
HH
H
H
H3C
H3C
H
H
III
H3C
H
CH3
H
IV
I>II>III>IV
I>V>II>III
I>V>III>IV
I>II>IV>III
None of the above
Continue to the Next Page
11
H
H3C
CH3
H
V
II. Draw all the possible isomers for 1-tert-butyl-4-methylcyclohexane. Arrange the order of
stability for these chair conformations. Briefly explain your reason. (10 points)
Next Page: Periodic Table & pKa Values
12
pKa Values for Some organic and Inorganic Acids
Acid
Formula
pKa
Conjugate Base
Ethane
CH3CH3
51
CH3CH2Ammonia
NH3
38
NH2Ethanol
CH3CH2OH
15.9
CH3CH2OWater
H2O
15.7
HOMethylammonium ion
CH3CH2NH3+
10.64
CH3CH2NH2+
Bicarbonate ion
HCO3
10.33
CO32Phenol
C6H5OH
9.95
C6H5OAmmonium ion
NH4+
9.24
NH3
Carbonic acid
H2CO3
6.36
HCO3Acetic acid
CH3CO2H
4.76
CH3CO2Benzoic acid
C6H5CO2H
4.19
C6H5CO2Phosphoric acid
H3PO4
2.1
H2PO4+
Hydronium ion
H3O
-1.74
H2 O
Sulfuric acid
H2SO4
-5.2
HSO4Hydrogen chloride
HCl
-7
ClHydrogen bromide
HBr
-8
BrHydrogen iodide
HI
-9
I-
13