Alkanes- Abstracted from Organic Chemistry Janice Smith 3rd edition

Chapter 4
1. What is the IUPAC name for the following compound?


A)
7,7 diethyl-5-isopropyl-3,4-dimethyldecane
B)
7,7-diethyl-5-isopropyl-2,3-dimethyldecane
C)
7,7-diethyl-4-isopropyl-2,3-dimethyldecane
Ans: B

2. Give the IUPAC name for the following compound.


A)
7,7-diethyl-2,4,5-trimethylnonane
C)
6-ethyl-2,4,5-trimethyloctane
B)
7-ethyl-2,4,5-trimethyloctane


Ans: A

3. Give the IUPAC name for the following compound.


A)
4,4-diethyl-2,3,6-trimethylnonane
C)
5,5-diethyl-2,3,6-trimethylnonane
B)
5,5-diethyl-4,7,8-trimethylnonane


Ans: C

4. Give the IUPAC name for the following compound.


A)
2,5-dimethyl-3-t-butylheptane
C)
2,5-dimethyl-4-t-butylheptane
B)
2,5-dimethyl-4-t-butylhexane


Ans: C

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5. Give the IUPAC name for the following compound.


A)
7-ethyl-6-isobutyl-3-methylundecane C)
7-ethyl-6-isobutyl-3-methyldecane
B)
7-ethyl-6-isobutyl-3-methylnonane


Ans: C

6. Give the IUPAC name for the following compound.


A)
5-sec-butyl-2,4-dimethylnonane
C)
6-sec-butyl-3,5-dimethyldecane
B)
6-sec-butyl-2,4-dimethyldecane


Ans: C

7. Give the IUPAC name for the following compound.

H
H C
CH
3
3
H
H

A)
2-methyl-4-isopropylheptane
C)
3-methyl-5-isopropylhexane
B)
2-methyl-4-isopropyloctane


Ans: A

8. Give the IUPAC name for the following compound.


A)
1-sec-butyl-4-isopropyl-2-methylcycloheptane
B)
1-sec-butyl-4-isopropyl-2-methylcyclohexane
C)
1-sec-butyl-3-isopropyl-3-methylcyclohexane
Ans: B

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9. Give the IUPAC name for the following compound.

H
H
H

A)
4-ethyl-5-isopropylnonane
C)
5-ethyl-4-isopropylnonane
B)
5-ethyl-4-isopropyloctane


Ans: C

10. Give the IUPAC name for the following compound.


A)
5-sec-butyl-7,7-diethyl-2,3-dimethyldecane
B)
4-sec-butyl-6,6-diethyl-2,3-dimethyldecane
C)
5-sec-butyl-7,7-diethyl-2,3-dimethylundedecane
Ans: A

11. Give the IUPAC name for the following compound.


A)
6-isobutyl-3,7-dimethyl-7-propyluncedecane
B)
4-isobutyl-2,5-dimethyl-5-propylnonane
C)
5-isobutyl-2,6-dimethyl-6-propyldecane
Ans: C

12. Give the IUPAC name for the following compound.



A)
4-isobutylyl-2-methylhexane
C)
4-isopropyl-2-methylheptane
B)
4-isopropyl-3-methylheptane


Ans: B

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13. Give the IUPAC name for the following compound.


A)
5,5-diethyl-2,3,6-trimethyldecane
C)
4,4-diethyl-2,3,6-trimethylnonane
B)
5,5-diethyl-2,3,6-trimethylnonane


Ans: B

14. Give the IUPAC name for the following compound.


A)
3,6-diethyl-4,4,5-trimethylnonane
C)
2,5-diethyl-3,3,4-trimethyloctane
B)
2,5-diethyl-3,3,4-trimethylnonane


Ans: A

15. The preferred conformation of cis-3-t-butyl-1-methyl-cyclohexane is one in which:
A)
the t-butyl group is axial and the methyl is equatorial.
B)
the methyl group is axial and the t-butyl group is equatorial.
C)
both groups are axial.
D)
both groups are equatorial.
E)
None of the choices are correct.
Ans: D

16. Which represents the ring-flipped conformer of a?

A) A B) B C) C D) D E) E
Ans: D

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17. Consider the molecule cis-1-ethyl-3-isopropylcyclohexane. Which is the overall
most-stable conformer?



A) A B) B C) C D) D E) E
Ans: C

18. Which of the following structures represents the most stable form of
1-isopropyl-2-methylcyclohexane?



A) A B) B C) C D) D E) E
Ans: D

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19. Select the most stable conformer of cis-1, 3-cyclohexane diol.


A) A B) B C) C D) D E) E
Ans: B

20. Rank the indicated conformations in order of decreasing stability.



A) A<B<C B) B<A<C C) C<A<B D) A<C<B E) C<B<A
Ans: A

21. Which conformation is the most stable?



A) A B) B C) C
Ans: C

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22. Which of the following conformations of 1,2-dibromoethane is the most stable?

H
H
Br
Br
H
Br
H
Br
H
Br
H
H
H
Br
Br
H
H
H
H
H
Br
H
H
H
A
B
C
D

A) A B) B C) C D) D
Ans: B

23. Given the three Newman projections drawn below, rank them in order of increasing
stability.



A) B<A<C B) C<A<B C) C<B<A D) B<C<A E) A<C<B
Ans: D

24. Rank the following conformations in order of increasing energy.


A) C < B < A B) B < A < C C) B < C < A D) A < B < C E) C < A <
B
Ans: A

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25. Assuming that the size of substituents is H<CH3<I, which of the following
conformations is the most stable?

CH
CH
CH
3
3
3
H
H
H
CH
3C
I
3
A
B
CH
C
3
H
H
H
H
H
H
I
H
I
CH
CH
3
3
I
I
H
D
H
E
H
H
H
H
H3C
CH3

A) A B) B C) C D) D E) E
Ans: C

26. Which of the following two conformers is higher in energy?



A) A B) B
Ans: B

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27. The graph below shows the energy changes that occur during rotation around the C-C
bond indicated in compound a. Which letter(s) on the graph correspond(s) to this
Newman Projection?


A) A and G B) B and F C) C and E D) D
Ans: D

28. Consider rotation about the indicated bond in the molecule below. Which Newman
Projection best represents the most stable conformer of the molecule during rotation
about the indicated bond?



A) A B) B C) C
Ans: A

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29. Which statement about the following conformers of the same compound is true?



A)
B is the most stable and A is the least stable.
B)
A is the most stable and B is the least stable.
C)
C is the most stable and A is the least stable.
D)
B is the most stable and C is the least stable.
E)
A is the most stable and C is the least stable.
Ans: E

30. How are the molecules below related to each other?



A)
They are constitutional isomers.
B)
They are identical.
C)
They are resonance structures.
D)
They are not isomers; they are different compounds.
E)
They are stereoisomers.
Ans: C

31. How are the molecules below related to each other?



A)
They are constitutional isomers.
B)
They are identical.
C)
They are resonance structures.
D)
They are not isomers; they are different compounds.
E)
They are stereoisomers.
Ans: A

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