Chapter 27, Problem 1E

Describe what is meant by each of the following reaction types, and illustrate with an example:
(a) nucleophilic substitution reaction: (b) electrophilic substitution reaction; (c) addition reaction;
(d) elimination reaction, (e) rearrangement reaction.

Interpretation Introduction

(a)

Interpretation:

The nucleophilic substitution reaction should be defined with example.

Concept introduction:

Nucleophilic substitution reaction describes the attack of the electron-rich group that is nucleophile on electron deficient groups that is electrophile.

Answer to Problem 1E

Nucleophilic substitution reaction is the type of reaction in which the nucleophile (electron rich species) attacks the electron-deficient carbon atom which is electrophilic.

Explanation of Solution

Nucleophilic substitution reaction is defined as an organic reaction which includes the attack of a nucleophile on electrophilic center along with the removal of the leaving group.

The example of the nucleophilic substitution reaction is,

${\text{C}}_{\text{2}}{\text{H}}_{\text{5}}\text{Cl}+{\text{OH}}^{-}\to {\text{C}}_{\text{2}}{\text{H}}_{\text{5}}\text{OH}+{\text{Cl}}^{-}$

In this reaction, chlorine of chloroethane is replaced by a hydroxyl group $\left({\text{OH}}^{-}\right)$.

Interpretation Introduction

(b)

Interpretation:

The electrophilic substitution reaction should be defined with example.

Concept introduction:

The electrophilic substitution reaction describes the displacement of functional group or hydrogen atom by an electron deficient group or electrophile.

Answer to Problem 1E

Electrophilic substitution reaction is defined as the organic reaction in which the electrophile replaces a functional group of a compound or hydrogen atom.

Explanation of Solution

Electrophilic substitution reaction is defined as the organic reaction which includes the replacement of functional group or $\text{H}$ atom by an electrophile.

Example of electrophilic substitution reaction is,

In this reaction, Toluene undergoes electrophilic substitution to form para nitrotoluene, meta nitrotoluene, and ortho nitrotoluene.

Interpretation Introduction

(c)

Interpretation:

The addition reaction should be defined with example.

Concept introduction:

The addition reaction describes the combination of two or more smaller molecules to form a larger molecule.

Answer to Problem 1E

Addition reaction is defined as the reaction in which two or more molecules combine to form a single and large molecule.

Explanation of Solution

The reaction of the addition of the two or more reactants that is A and B to produce a single product C is termed as addition reaction.

The example of addition reaction is,

In this reaction, chlorine molecule combines with ethene to form 1, 2-dichloroethane.

Interpretation Introduction

(d)

Interpretation:

The elimination reaction should be defined with example.

Concept introduction:

The elimination reaction describes the removal of two substituents from the reactant molecule to form the product.

Answer to Problem 1E

Elimination reaction is the reaction by which the reactant molecule or compound breaks into two or more products.

Explanation of Solution

Elimination reaction is the type of reaction in which two substituents are removed from the reactant molecule to form the product. Generally, unsaturated compounds are formed in an elimination reaction.

The example of the elimination reaction is,

The reaction of cyclohexanol in the presence of ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ and heat to form cyclohexene is an elimination reaction.

Interpretation Introduction

(e)

Interpretation:

The rearrangement reaction should be defined with example.

Concept introduction:

The rearrangement reaction describes the rearrangement of bonds in a molecule to form the product.

Answer to Problem 1E

It is the process of movement of bonds within a molecule to give rise to structural isomers.

Explanation of Solution

It is defined as a reaction in which an atom or a bond migrates from one atom in reactant molecule to adjacent atom to give rise to the product.

Example of rearrangement reaction is,

The glyceraldehyde undergoes rearrangement to form enediol. $\text{Prop-1-ene-1,2,3-triol}$ is a structural isomer of the glyceraldehyde.