Question

Differentiate between addition reaction and substitution reaction. Give one example each.

Answer 1

The addition reaction and substitution reaction are the types of chemical reaction which differ from each other. In addition reaction takes place in unsaturated compounds while the substitution reaction takes place in saturated compounds.

Complete step by step answer:
When any two compounds with different or similar properties react with each other under influence of external conditions like pressure, temperature and reagents to form a new compound of different property is called a chemical reaction.
The chemical reaction may be of different types: addition reaction, substitution reaction, elimination reaction, decomposition reaction and many more.
An Additional reaction is defined as the reaction where two compounds combine to form a new compound without losing any of its atoms. In this reaction weaker pi-bond is converted to form two new sigma bonds. The addition reaction is further divided into electrophilic addition reaction and nucleophilic addition reaction.
Substitution reaction is defined as the reaction where replacement of an atom or group from the reactant compound takes place by another atom or group to form a new product. The substitution reaction is further divided into electrophilic substitution reaction and nucleophilic substitution reaction.
The difference between addition reaction and substitution reaction is shown below.
Addition reaction:
-The additional reaction is shown by unsaturated hydrocarbons which contain double or triple bonds.
-The additional reaction is used to convert unsaturated compounds into saturated compounds.
-Example of addition reaction is hydration reaction. In this reaction ethene reacts with water to form ethanol.
The reaction is shown below.
$C{H_2} = C{H_2} + {H_2}O \to C{H_3}C{H_2}OH$
Substitution reaction:
-The substitution reaction is shown by saturated hydrocarbon which contains a single bond.
-In substitution reaction, there is no conversion of saturated hydrocarbons to unsaturated hydrocarbons.
-Example of substitution reaction is halogenation of alkanes. In this reaction methane reacts with chlorine to form methyl chloride and hydrochloric acid.
The reaction is shown below.
$C{H_4} + C{l_2} \to C{H_3}Cl + HCl$

Note: In both the addition reaction and substitution reaction, electrophilic group and nucleophilic group play a very major role. Despite having conjugated double bonds, the aromatic hydrocarbon shows electrophilic substitution reaction but other compounds with unsaturated group apart from aromatic hydrocarbons give electrophilic addition reaction.