Page 3 - LN

b. Substitution reaction-

Alkanes are the hydrocarbons having only carbon-carbon single bonds [C-C] which
are strong and stable bonds.
As they aresaturated, stable compounds, the C-C bond does not break up easily.

So they undergo Substitution reactions whereHydrogen atom of an alkane is
substituted/replaced by another more reactive atom or group of atoms(functional
groups).

 For example-
Alkanes undergo substitution reaction with halogens in the presence of light.

For instance, in ultraviolet light , methane reacts with halogen molecules such as
chlorine and bromine to form the corresponding Halo derivative.
This reaction is a substitution reaction because one of the hydrogen atoms from the
methane is replaced by a chlorine/bromine atom.

Example- Chlorination of Methane:

3