Question

Define or explain chain isomerism with an example.

Answer 1

Chain isomerism is the term used to describe a condition where two or more compounds have a similar chemical formula but differ in the arrangement of carbon atoms in straight or branched chains.

Example:

Pentane (C₅H₁₂)

\[\ce{\underset{Pentane}{CH3 - CH2 - CH2 - CH2 - CH3}}\]

\[\begin{array}{cc}
\ce{CH3}\phantom{.......}\\
|\phantom{.........}\\
\ce{\underset{iso pentane (2, methyl butane)}{CH3 - CH - CH2 - CH3}}
\end{array}\]

\[\begin{array}{cc}
\phantom{..}\ce{CH3}\\
|\\
\ce{CH3 - C - CH3}\\
|\\
\phantom{...}\ce{\underset{[2, 2-dimethyl propane]}{\underset{neo-pentane}{CH3}}}\\
\end{array}\]