Question

Define the substitution reaction. Give an example.

Answer 1

A reaction in which one atom of a molecule is replaced by another atom (or group of atoms) is called a substitution reaction.

Example:

The action of methane with chlorine in the presence of sunlight.

\[\begin{array}{cc}
\ce{H}\phantom{.......................}\ce{H}\phantom{.......}\\
\phantom{.}|\phantom{........................}|\phantom{........}\\
\ce{H - C - H + Cl2 ->[diffused][sunlight] H - C - Cl + HCl}\\
\phantom{.}|\phantom{........................}|\phantom{........}\\
\ce{\underset{Methane}{H}}\phantom{................}\ce{\underset{Chloromethene}{H}}\phantom{.....}\\
\end{array}\]

A chlorine atom replaces one atom of hydrogen to form chloromethane.