The document explains nucleophilic substitution, a chemical reaction where a nucleophile replaces a functional group in an electrophile. It details two types of nucleophilic substitution: SN1, which is unimolecular and involves a two-step process, and SN2, which is bimolecular and occurs in one step. Key differences between SN1 and SN2 reactions, including their mechanisms and conditions, are also highlighted.

1. Ram-Eesh Institute of Vocational & Technical Education
Submitted to -
Dr. Sandeep Bansal sir

2. Nucleophilic substitution
“In this chemical reaction when from alkyl halide the nucleophilic molecules is replaced by another
nucleophilic atom that is called of nucleophilic substitution.”.
nucleophilic substitution is a class of chemical reactions in which an electron-rich chemical
species (known as a nucleophile) replaces a functional group within another electron-
deficient molecule (known as the electrophile). The molecule that contains the electrophile
and the leaving functional group is called the substrate.
The most general form of the reaction may be given as the following:

3. Types of nucleophilic substitution -
There are two type of nucleophilic substitution -
● SN 1 nucleophilic substitution
● SN 2 nucleophilic substitution

4. 1- SN 1 nucleophilic substitution -
● Which rate of reaction depends on the alkyl halide is called as sn 1 reaction.
● The SN1 reaction is a nucleophilic substitution reaction where the rate-determining step is
unimolecular. It is a type of organic substitution reaction. SN1 stands for substitution nucleophilic
unimolecular.
● Any chemical reaction depends on the alkyl halide .
● Rate of reaction is directly proportional to alkyl halide.

6. Properties -
● Two step process
● First order of reaction
● Do not depends on nucleophilic substitution but depends on the alkyl halide
● Territory alkyl halide
● Same as a sterochemistry

7. 2- SN 2 nucleophilic substitution -
● The SN2 reaction is a nucleophilic substitution reaction where a bond is broken and another is
formed synchronously. Two reacting species are involved in the rate determining step of the
reaction.
● Those nucleophilic substitution reaction in which the rate of reaction depends on the alkyl halide or
nucleophilic substitution.
● Rate of reaction is directly proportional to two alkyl halide.

9. Properties-

10. Difference between Sn1 &Sn 2 nucleophilic substitution -
● It is unimolecular reaction
● It is two step process
● Formation of carbonation intermediate
take place
● Rearrangement take place
● First step is slow and rate determinimg
step
● Racemic mixture is formed
● Take place protic solvent like water
● Biomolecular reaction
● Only one step
● Formation of transition state take place
● No rearrangement take place
● Only one step mechanism
● Wolden inversion take place
● Take place in first order alkyl halide
● Favourable in polar aprotic solvent like
acetone