Chapter 22, Problem 69A

(a)

Interpretation Introduction

Interpretation- To identify the double bond

Concept Introduction-

Covalent bond is formed when electrons are shared between two non-metals. It can be of following type:

1. Single bond − it contains one sigma bond
2. Double bond − it contains one sigma and one pi bond
3. Triple bond − it contains one sigma and two pi bonds.

Explanation of Solution

Double bonds is identified as one sigma and one pi bond.

Hence, double bond is labelled as $3$

(b)

Interpretation Introduction

Interpretation- To identify the phenyl group Introduction −

Alkyl groups: these are derived when one hydrogen atoms is removed from alkane molecule.

Example: Methyl ${\text{CH}}_{\text{3}}$ is derived from methane ${\text{CH}}_4$ when one hydrogen atoms is removed.

Explanation of Solution

Phenyl ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}$ group is alkyl group derived from benzene ${\text{C}}_{\text{6}}{\text{H}}_6$ molecule.

Hence in the given molecule phenyl group is labelled as $1$

(c)

Interpretation Introduction

Interpretation- To identify the methyl group

Introduction-

Alkyl groups: these are derived when one hydrogen atoms is removed from alkane molecule.

Example: Phenyl ${\text{C}}_{\text{6}}{\text{H}}_5$ group is alkyl group derived from benzene ${\text{C}}_{\text{6}}{\text{H}}_6$ molecule.

Explanation of Solution

Methyl group ${\text{CH}}_3$ is derived from methane ${\text{CH}}_4$ molecule when one hydrogen is removed.

Hence methyl group is labelled as $5$

(d)

Interpretation Introduction

Interpretation- To identify an asymmetric carbon.

Introduction-

Asymmetric carbon − Carbon atom when have four different group is asymmetric.

Example :

Explanation of Solution

The carbon atom labelled $4$ as is asymmetric since it has four different groups, $\text{C,F,Cl,Br}$ .

(e)

Interpretation Introduction

Interpretation- To identify the propyl group

Introduction −

Alkyl groups: these are derived when one hydrogen atoms is removed from alkane molecule.

Example: Methyl ${\text{CH}}_3$ is derived from methane ${\text{CH}}_4$ when one hydrogen atoms is removed.

Explanation of Solution

Propyl group ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}$ is derived from propane ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}$ when hydrogen atom is removed.

Hence propyl group is labelled as $2$