Download Unit C Lesson 5 Alcohols

Hydrocarbon Derivatives

Organic compounds are classified according to their functional group.

A functional group is a special arrangement of atoms that is mainly responsible for
the chemical behaviour of the molecule.

The functional group of various organic families are shown in the following table:
Alcohols

An alcohol is a hydrocarbon derivative that contains the hydroxyl (-OH) functional
group.

Naming and Drawing Alcohols:
 Identify the root
 Locate the longest chain that includes the hydroxyl group. Name
the parent alkane.
 Identify the suffix
 The suffix always ends with –ol. The position of the hydroxyl
group is indicated by a number in front of the –ol.
 The numbering of the parent chain begins at the end of the chain
nearest the hydroxyl group.
 If there is more than one hydroxyl group, use a prefix (di,tri, tetra,
etc.) to indicate the number of hydroxyl groups. A number for
each hydroxyl group is required.
 If the suffix begins with a vowel, drop the –e on the end of the
parent alkane. If the suffix begins with a consonant, do not drop
the –e.
 Identify the prefix
 Name and number any alkyl side groups on the main chain.

EX. Name the following compound

EX. Name the following compound

EX. Name the following compound

EX. Name the following compound

EX. Draw the structure of 3-methylbutan-2-ol

EX. Draw the structure of 2-ethylcyclopentanol

EX. Draw the structure of 3,3-diphenylhexane-2,4-diol.

EX. Draw the structure of 2,4-dimethylnonan-3-ol.
Physical Properties of Alcohols

The hydroxyl group is very polar. This allows the smallest of the alcohols (methanol
and ethanol) to be miscible with water.

As the hydrocarbon chain becomes longer, the non-polar characteristics of the chain
cause the larger alcohols to be less soluble in water.

The hydrogen bonding between the hydroxyl groups of neighbouring molecules
results in much higher boiling points than in similar sized alkanes.

All straight-chain alcohols with fewer than 12 carbon atoms are liquids at standard
temperatures.
Alkyl Halides

An alkyl halide is a hydrocarbon derivative that contains at least one halogen (Group
17) atom.

Chlorofluorocarbons (CFC’s) are a group of alkyl halides that deplete the ozone layer
as well as being greenhouse gases.

Naming and Drawing Alkyl Halides:
 Identify the root
Locate the longest chain that includes the halogen atom(s). Name the
parent alkane.
 Identify the prefix
Number the parent chain starting at the end nearest the halogen atom.
Name and number any alkyl side groups.
Insert the number(s) of the carbon atom(s) bonded to the halogen(s).
Use the prefix(es) that identify the specific halogen(s) (chloro-, fluoro-,
bromo-, iodo-)
If there are two or more of the same type of halogen, use a prefix to
indicate the number (di, tri, tetra)
If there is more than one type of halogen, list them alphabetically.

EX. Name the following compound

EX. Name the following compound

EX. Name the following compound

EX. Draw the structure of 2,3-dibromo-3,4-difluoroheptane.

EX. Draw the structure of 1,1-dichloro-2-fluorocyclopentane

EX. Draw the structure of 1,3,5-triiodobenzene
Chem 30
Alcohols and Alkyl Halides
1. Name each of the following molecules:
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
2. Draw each of the following:
(a) methanol
(b) propan-2-ol
(c) bromoethane
(d) butane-2,2-diol
(e) 2,3,4-trichloro-3,4-dimethylheptane
(f) 3-methyl-4-propyloctan-1-ol
(g) 2,3-dimethylcyclobutanol
(h) 1,4-difluorobenzene
(i) 3-chlorocyclopentene