CHE 275

ALKANES AND CYCLOALKANES:

INTRODUCTION TO HYDROCARBONS

1. Which of the following structures contain the sec-butyl group?

A.

B.

C.

D.

E.
2. Choose the correct IUPAC name for the following molecule.
A.
B.
C.
D.
E.

4,8-dimethyl-3-propylundecane
4,8-dimethyl-9-propylundecane
4,8-dimethyl-9-ethyldodecane
9-ethyl-4,8-dimethyldodecane
4-ethyl-5,9-dimethyldodecane

3. What would the correct name of the following molecule be?

A.
B.
C.
D.
E.

3-(2-butyl)-pentane
3-ethyl-4-methylhexane
2,3-diethylpentane
3-methyl-4-ethylpentane
3,4-diethylpentane

4. Which of the following hydrocarbons would you expect to have the lowest boiling point?

A.

B.

C.

D.

E.
5. The hydrocarbon that has only 1 and 4 carbons is:
A. hexane

B. 2-methylpentane

C. 2,2-dimethylpropane

D. 2,3-dimethyllbutane

CHAP 2 ASSIGN

6. Which of the following molecules has six tertiary hydrogen atoms?

A.

B.

C.

D.

E.
7. Which of the following structures can be described as cis ?

8. What is the correct IUPAC name of the compound shown on

the right?
A.
B.
C.
D.

4,6-dimethyl-6-ethylpentane
2,4-dimethyl-2-ethylheptane
3,3,5-trimethyloctane
4,6-dimethyl-6-isobutylpentane

9. A constitutional isomer of C5H12 forms four structurally different monochloro derivatives. What is the name of this
isomer?
10. Which of the following is bicyclo[3.2.2]nonane?
A.
B.
C.
D.
E.

I
II
III
IV
V

II

IV
11. Which of the following pairs of compounds represent pairs of constitutional isomers?
A. 2-methylbutane and pentane
C. sec-butyl bromide and tert-butyl bromide
E. all of the above

B. 2-chlorohexane and 3-chlorohexane

D. propyl chloride and isopropyl chloride

III

12. Select the systematic name for

A.
B.
C.
D.
E.

cis-1,3-dichlorocyclopentane
trans-1,4-dichlorocyclopentane
cis-1,2-dichlorocyclopentane
trans-1,3-dichlorocyclopentane
1,1-dichlorocyclopentane

Cl

Cl

CH3CHCH2
CH2CH3 is:

13. An IUPAC name for the group

A. isopentyl

B. isoamyl

C. sec-butylmethyl

D. 2-methylbutyl

E. 2-ethylpropyl

Br
Cl is:

14. The correct IUPAC name for

A. 2-bromo-4-chloro-4-isopropylpentane
C. 5-bromo-3-chloro-2,3-dimethylhexane
E. 2-(2-bromopropyl)-2-chloro-3-methylbutane

B. 4-bromo-2-chloro-2-isopropylpentane
D. 2-bromo-4-chloro-4,5-dimethylhexane

15. Select the reagents necessary to convert 3-bromohexane into hexane.

A. Zn, H+

B. CuI

C. H2O

D. H3O+

E. OH-

16. Catalytic hydrogenation of which of the following will yield 2-methylpentane?

A. 2-methyl-1-pentene
C. 4-methyl-2-pentene
E. All of the above

B. 2-methyl-2-pentene
D. 4-methyl-1-pentene

17. The C-C sigma bond in acetylene is formed by the overlap of which two orbitals?

A. 2p-2p

B. sp-sp

C. sp2-sp2

D. sp3-sp3

18. Which one of the following is 2,2,5-trimethylhexane?

A. (CH3)2CHCH2C(CH3)3
C. (CH3)2CHCH2CH2C(CH3)3

B. CH3CH2CH(CH3)C(CH3)3
D. (CH3)2CHCH2 CH2CH2C(CH3)3

19. The correct name of the following compound is

A.
B.
C.
D.

(1-methylpropyl)cyclohexane.
(2,2-dimethylethyl)cyclohexane.
(2-methylpropyl)cyclohexane.
(2,2-dimethylpropyl)cyclohexane.

20. The boiling point of isobutane (-10.2C) is lower than n-butane (-0.4C) because isobutane has
A.
B.
C.
D.

weaker intermolecular van der Waals forces.

stronger intermolecular van der Waals forces.
weaker dipole-dipole attractive forces.
stronger dipole-dipole attractive forces.

21. A tertiary carbon atom is present in which of these compounds?

A.
B.
C.
D.
E.

I
II, IV
III, V
IV
All of these

Cl

Cl

II

III

OH
HO

IV

22. Rank the following in order of decreasing oxidation state of carbon (most to least oxidized).
CH3CH3
2

HCCH
1
(a) 2 > 1 > 3

(b) 1 > 3 > 2

(c) 1 > 2 > 3

CH2=CH2
3
(d) 2 > 3 > 1

23. Which of the following reactions requires an oxidizing agent?

(a) RCH2OH RCH2Cl
(c) RCH2Cl RCH3
(e) none of these

(b) RCH=CH2 RCH2CH3

(d) RCH2OH RCH=O

24. Carbon atoms 1, 2, and 3 in the following structure are classified, respectively, as
A.
B.
C.
D.

tertiary, primary, secondary.

quaternary, primary, tertiary.
quaternary, secondary, secondary.
quaternary, secondary, tertiary.

25. The heats of combustion of heptane and 3,3-dimethypentane are -4,817 and -4,809 kJ/mol, respectively. Which
statement is true?
A.
B.
C.
D.

Heptane is 8 kJ/mol more stable then 3,3-dimethylpentane.

3,3-Dimethylpentane is 8 kJ/mol more stable than heptane.
Stabilities cannot be compared since they are not isomers.
Stabilities cannot be compared since they give different combustion products.

26. The systematic name of the following group is

A.
B.
C.
D.

5-ethyl-2-methylpentyl.
1-ethyl-4-methylpentyl.
6-methyl-3-heptyl.
2-methyl-5-heptyl.

27. What is the relationship between the two structures below?

A.
B.
C.
D.

identical structures
resonance forms
constitutional isomers
different compounds with different compositions

28. The lowest-boiling isomer of C7H16 would be

29. What is the relationship between the following two structures?

A.
B.
C.
D.

identical structures
resonance forms
constitutional isomers
different compounds with different compositions

30. Which of the molecules below is not an isomer of formula C6H14?

EXTRA CREDIT
31. How many alkanes of formula C7H16 possess a quaternary carbon atom? Show with bond-line formulas.
A. 1

B. 2

C. 3

D. 4

E. 5

32. An unknown compound with a molecular formula of C 8H18 reacts with chlorine in the presence of light and heat. From the
reaction mixture only one monochlorination product (i.e., only one compound with the formula C8H17Cl) can be isolated.
What is the most likely structure of the original unknown compound?

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SSI 2015