Name the important chemical reactions of hydrocarbons. Give one example for each.

Important chemical reactions of hydrocarbons are:

i. Substitution reaction:

Reaction in which an atom or a group in a compound is replaced by another atom or group are called substitution reactions.

Example:

Methane Chloromethane

In the above example, one hydrogen atom of methane is replaced by one chlorine atom.

ii. Addition reaction

When an unsaturated hydrocarbon reacts with hydrogen, gives a saturated hydrocarbon. This reaction is called addition reaction.

Example:

CH₂ = CH₂ + H₂→ CH₃—CH₃

(unsaturated) (saturated)

iii. Polymerization

Polymerization is a process in which a large number of simple molecules combine under suitable conditions to form complex molecules. The molecules formed are called polymers.

Example:

In the above reaction, a large number of ethene molecules combine under higher pressure in the presence of catalyst to form polythene.