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Solving Problems: A Chemistry Handbook
Chemistry: Matter and Change
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SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER 21
Example Problem 21-1
Naming Branched-Chain Alkanes
Name the following alkane.
a. The longest chain has eight carbon atoms, so the parent name
is octane.
b. Number the chain in both directions.
In both cases, the first branch point occurs at position 3. The
numbering on the right results in a lower position (4) for the
second branch point, so this numbering will be used.
c. Identify the attached groups. There is a methyl (—CH 3 ) group
at position 3 and ethyl (—CH 2 CH 3 ) groups at positions 4 and 6.
The name of the alkane is 4,6-diethyl-3-methyloctane. The
prefix di- indicates that there are two ethyl groups, and alphabetical order places ethyl before methyl in the name of the
compound.
Practice Problems
1. Name the compound represented by each of the following
condensed structural formulas.
a.
b.
c. CH 3 CH 2 CH 2 CHCH 2 CH 2 CHCH 2 CH 3
CH 2 CH 3 CH 2 CH 2 CH 3
CH 3 CHCH 2 CHCHCH 3
CH 3
CH 3
CH 2 CH 3
CH 3 CH 2 CHCH 3
CH 3
1 2 3 4
5
6
7 8
CH 3 CH 2 CHCH 2 CHCHCH 3
CH 2 CH 3 CH 2 CH 3
CH 2 CH 3
8 7 6 5
4
3
2 1
CH 3 CH 2 CHCH 2 CHCHCH 3
CH 2 CH 3 CH 2 CH 3
CH 2 CH 3
CH 3 CH 2 CHCH 2 CHCHCH 3
CH 2 CH 3 CH 2 CH 3
CH 2 CH 3