Question

difference between synthesis reaction and a substitution reaction

Answer 1

Although the name suggests, addition reaction is a reaction in which, any group(s)is added to the substrate; whereas, Substitution reactions include reactions in which a group is replaced/substituted by another group, there also comes another huge difference between the two.

Answer 2

Addition reactions, substitution reactions, and elimination reactions are fundamental reactions in organic chemistry. Most chemical synthesis and identifications are based on these reactions. These reactions can occur in either one step or two steps. The main difference between addition and substitution reactions is that addition reactions involve the combination of two or more atoms or functional groups whereas substitution reactions involve the displacement of an atom or a functional group by another functional group.