Difference Between SN1 and SN2

To understand the difference between SN1 and SN2, it is important to know their definitions first. SN1 and SN2 are generally confused for being one and the same, however there are certain defining characteristics that separates SN1 from SN2. Considered both as nucleophilic substitution reactions, these are reactions involving the donor from an electron pair and an acceptor. The solvent present plays a very important role in exactly postulating the path of the reaction. Understanding the physical properties of Haloalkanes, is essential in understanding SN1 and SN2.

Difference between SN1 and SN2

The major difference involved between these two types of reactions is to study the different properties of the departure group that helps us in finding out the pathway of the group. Understanding the major differences between these two will give us the key differences between one and the other. For a full list of differences between the two, check out the tabular column below:

Difference between SN1 and SN2



The rate of reaction is unimolecular.

The rate of reaction is bimolecular

It is a two step mechanism

It is only a one step mechanism

Carbocation is formed as an intermediate part of the reaction.

No carbocation is formed during the reaction.

There is no partial bond formed with the carbon during this reaction.

Carbon forms a partial bond with the nucleophile and the leaving group.

There are many steps in this reaction which start with the removal of the group while attacking the nucleophile.

The process takes place in only one cycle, with a single intermediate stage.

Thus, these are the key differences between SN1 and SN2. To know more in depth about chemistry related topics, download the BYJU’s app today! Check out our chemistry related topic below:


Practise This Question

Which of the following is incorrect?