CHEM 122: Introduction to Organic Chemistry
Chapter 4: Benzene and its Derivatives.
1. Draw at least two structural formulas for each of the following. (Several
constitutional isomers are possible for each part.)
a)
b)
c)
d)
An alkene of six carbons
A cycloalkane of six carbons
An alkyne of six carbons
An aromatic hydrocarbon of eight carbons
2. Account for the fact that the six-membered ring in benzene is planar but the sixmembered ring in cyclohexane is not.
3. The compound 1,4-dichlorobenzene (p-dichlorobenzene) has a rigid geometry
that does not allow for free rotation. Yet no cis-trans isomers exist for this
structure. Explain why it does not show cis-trans isomerism.
4. Name these compounds.
NO 2
CH3
a)
Cl
Cl
b)
c) C6H5CH2CH2CH2Cl d) C6H5CCH2CH3
CH3
CH3
NH 2
OH
NO 2
e)
Cl
C6 H5
f)
g)
C=C
H
h)
C6H5
Cl
5. Draw structural formulas for these compounds.
a)
b)
c)
d)
e)
f)
1-Bromo-2-chloro-4-ethylbenzene
4-Bromo-1,2-dimethylbenzene
2,4,6-Trinitrotoluene
4-Phenyl-1-pentene
p-Cresol
2,4-Dichlorophenol
6. Following is the structural formula of styrene, the monomer from which the
polymer polystyrene is prepared.
CH=CH 2 polymerization
Polystyrene
Styrene
Draw a section of a polystyrene chain showing at least three monomer units.
7. Suppose you have unlabeled bottles of benzene and cyclohexene. What chemical
reaction could you use to tell which bottle contains which chemical? Explain
what you would do, what you would expect to see, and how you would explain
your observations. Write an equation for a positive test.
8. Two products with the molecular formula C6H4BrCl form when bromobenzene is
treated with chlorine, Cl2, in the presence of FeCl3 as a catalyst. Name and draw
a structural formula for each product.
9. What reagents and/or catalyst are necessary to carry out each conversion?
a) Benzene to nitrobenzene
b) 1,4-dichlorobenzene to 2-bromo-1,4-dichlorobenzene
c) Benzene to aniline
10. What reagents and/or catalyst are necessary to carry out each conversion? Each
conversion requires two steps.
a) Benzene to 3-nitrobenzenesulfonic acid
b) Benzene to 1-bromo-4-chlorobenzene
11. Aromatic substitution can be done on naphthalene. Treatment of naphthalene
with concentrated H2SO4 gives two (and only two) different sulfonic acids. Draw
a structural formula for each.
12. Both phenol and cyclohexanol are only slightly soluble in water. Account for the
fact that phenol dissolves in aqueous sodium hydroxide but cyclohexanol does
not.
13. The structure for naphthalene given below is only one of three possible resonance
structures. Draw the other two.
Naphthalene
14. Draw structural formulas for these compounds.
a)
b)
c)
d)
e)
f)
1-Phenylcyclopropanol
Styrene
m-Bromophenol
4-Nitrobenzoic acid
Isobutylbenzene
m-Xylene
15. Write the structural formula for the product of each reaction.
HNO3
H2SO4
a)
CH3
Br2
FeBr3
CH3
b)
Br
c)
H2SO4
Br
16. Styrene reacts with bromine to give a compound with the molecular formula
C8H8Br2. Draw a structural formula for this compound.