Organic Chemistry

Branched chains

18.3 Isomerism.

The atoms in alkanes with more than three carbon atoms can be arranged in many ways,
leading to a large number of potential different configurations (isomers). So-called ”normal”
alkanes have a linear, unbranched configuration, but then-isomer of any given alkane is
only one of potentially hundreds or even possibly millions of configurations for that number
of carbon and hydrogen atoms in some sort of chain arrangement.
Isomerism is defined as the compound having same moleculer formula the formula which
present the different moleculer formula arrangement are called as Isomerism.
e.g.- The molecular formula for butane is C 4 H 10.

The number of isomers increases rapidly with the number of carbon atoms in a given alkane
molecule; for alkanes with as few as 12 carbon atoms, there are over three hundred and
fifty-five possible forms the molecule can take!

# Carbon Atoms # Isomers of Alkane

1 1

2 1

3 1

4 2

5 3

6 5

7 9

8 18

9 35

10 75

11 159

12 355

18.4 Branched chains

Carbon is able to bond in all four directions and easily forms strong bonds with other carbon
atoms. When one carbon is bonded to more than two other carbons it forms a branch.