EXAM # 1 Sample
Organic Chemistry I
2423
Amantadine- an antiviral drug used as an antiviral and
antiparkinsonic.
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SAMPLE ORGANIC CHEM 2423 EXAM #1A
DIRECTIONS- Please answer all questions in the space provided as completely and clearly as possible .
Show all your work for the writing portions of the exam.
PART I- Multiple Choice (3 points each)
____1. How would you best describe the C-C bonds in H3C-CH2 -CH3?
A. sp3-sp2
B. sp2-sp3
C. sp3-sp3
D. sp-sp
____2. Which of the following molecules contains an sp-hybrized C-atom?
A. CH2O
B. CH2CH2
C. CH3NH2
D. HCN
____3. Which of the following statement is(are) correct?
A. the maximum number of electrons possible for a set of p-orbitals is 6?
B. the ground state electron configuration of carbon 1s2 2s2 2px1 2py1 2pz0 .
C. the total number of bonding electron pairs in BF3 is 3.
D. All of these
____4. What is the formal charge on the N-atom in nitromethane, CH3NO2, in the
most important resonance forms of this molecule?
B. –2
A. +1
C. –1
D. +2
____5.Which one of the following IUPAC name does not represent an acceptable
name of propanol, C3H8O?
A. 1-Propaanol
C. 3-Propanol
B. 2-Propanol
D. All of them
____6. Which is the correct order of decreasing bond polarity? (Consider the
electronegativities of the halogens.)
A. H-F < H-Cl > H-Br > H-I
C. H-F > H-Cl < H-Br < H-I
B. H-F < H-Cl < H-Br < H-I
D. H-F > H-Cl > H-Br > H-I
____ 7. Which of the following conformation is the most stable conformation of butane, view the
molecule from the central carbons?
CH3
H
H
H
H
CH3
I
CH3
CH3
H
H
H
H
CH3
H
CH3
H
H
II
III
2
H
A. I only
B. II only
C. III only
D. all of these
____ 8. Which of the following cyclohexane conformation is(are) consider to be cis
conformation?
A. I only
III
II
I
B. II only
C. I and II
D. I, II, and III
____ 9. Which of the following isomers of pentane has a tertiary carbon?
A. 2-methylbutane
C. 2,2-dimethylpropane
B. n-pentane
D. None of these
____10. Which structure is tert.-butyl bromide?
A. Br-CH(CH3)-CH2-CH3
B. Br-C(CH3)3
C. Br-CH2-CH(CH3)2
D. Br-C(CH3)2-CH2-CH3
____11. Which one of the alkanes would you suspect to have the lowest boiling point?
A. 2-methylpropane
B. pentane
C. nonane
D. butane
____ 12. Which reaction describes the complete combustion of propane?
A.
B.
C.
D.
C3H8 + 5 O2
C3H8 + 3 O2
C3H8 + 3.5 O2
C3H8 + 4.5 O2
3 CO2 + 4 H2O
3 CO2 + 3 H2O
3 CO + 4 H2O
3 CO2 + 3 H2O
____13. Which conformation of cyclohexane corresponds to the most stable
structure?
A. half chair
B. chair
C. twist-chair
D. none of these
____14. Name the compound CH3-C(CH3)2-CClH-CH3 according to IUPAC
nomenclature.
A. 3-chloro-1,2-dimethylbutane
B. 3-chloro-2,2-dimethylbutane
C. 3-chloro-2,2-diethylbutane
D. 2-chloro-3,3-dimethylbutane
____15. Which of the following molecules can have Gauche interaction during rotation between C2 and C3.
A. Ethane
B. n-Butane
C. n-Propane
D. All of them
____16. An axial methyl group in cyclohexane suffers from what disadvantage?
A. one 1,3-diaxial interactions
C. two 1,3-diaxial interactions
B. two 1,2-diaxial interactions
D. one 1,2-diaxial interactions
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____17. Among the following pairs of isomers, identify the pair of constitutional
isomers.
A. 2-Methlpentane and n-Hexane
B. 2-Methylbutane and n-Pentane
C. Ethanol and Diethylether
D. 1,2-Dimethylbutane and 2,2-dimethylbutane
E) All of them
____18. How many tertiary hydrogen atoms are there in Cl-CH2-C(CH3)2-CH(CH3)-C(CH3)3?
A. 6
B.3
C. 2
D. 1
____19. Consider the structure of trans-1,2-dimethylcyclohexane. Which statement
is fully correct?
A. Trans methyl groups favor chair and both are equatorial.
B. Trans methyl groups favor chair and both are axial.
C. Trans methyl groups favor the plane conformation.
D. Trans methyl groups favor chair and are axial and equatorial.
____20. Which statement is written incorrectly?
A. Acetic acid (pKa =4.73) is stronger acid than water(pKa =15.75).
B. The conjugate acid to (CH3)3N: is (CH3)3NH+.
C. An electron pair donor substance considers being a Lewis acid.
D. The stronger the acid, the lower the pKa value
PART II- Show your work (8 points each)
21. Name the Structures
CH3CH2
_______________________________
CH3
__________________________________
Structure of the names
cis- 1-ethyl-3-methylcyclohexane
5-ethyl-4-isopropyldecane
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22. Draw all the possible resonances (at least two) for the following compound:
CH3
..
23. Identify the functional groups in the following compound and name each functional group.
CO - O - CH2 -CH3
O - CH = CH3
24. Complete the following reactions and write the possible products.
C6H14
+ O2
CH4
+
Cl2
25. Draw possible Newman projections and saw horse projections of n–Butane and indicate the most stable
conformer
BONUS Question(10 points)- Show all your work.
Please draw five isomers (constitutional or/and geometrical) of cyclobutane derivatives of the formula C5H9Cl.
Please name each isomer.
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ORGANIC CHEM 2423 EXAM #1B ( Answers)
1. C 2. D 3. D 4. A 5. C 6. D 7. A 8. A 9. A 10. B
11. A 12. A 13. B 14. B 15. B 16. C 17. E 18. D 19. A 20. C
trans –1-ethyl-3- methylcyclohexane
21. Naming: 3,4-diethyloctane
Structures :
CH2CH3
CH3
22.
CH3
CH3
CH3
..
..
23.
CO - O - CH2 - CH3
ester
alkene
aromatic
O - CH = CH2
ether
24. 2C6H14 + 19O2  12CO2 + 14H2O
CH4
+ Cl2 
CH3Cl + HCl
25. Refer to your notes
Bonus: Refer to your notes
6
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