Name: Physical Properties of Diazonium Salts
Uploaded: 2019-07-19
Duration: 3 min 26 s
Description: Diazonium Salts are of great importance in organic chemistry as they are required to synthesise several other organic compounds. Let’s explore their physical...

Question

Arrange the following in the increasing order of their pKb values : $C_{6} H_{5} {NH}_{2}, C_{2} H_{5} {NH}_{2}, C_{6} H_{5} {NHCH}_{3}$

Accepted Answer

The increasing order for pKb values is $C_{2} H_{5} {NH}_{2} (3.29) < C_{6} H_{5} {NHCH}_{3} (9.30) < C_{6} H_{5} {NH}_{2} (9.38)$ . The numbers in bracket indicates pKb. Higher is the pKb value, lower is the basic strength of amine. Thus, the increasing order for pKb values indicates decreasing order of the basic strength of amine. Aniline is least basic and ethanamine is most basic.
Aniline is least basic as unshared pair of electrons on N atom is involved in resonance with benzene ring and cannot be easily donated. When an alkyl group such as methyl or ethyl is present, the electron releasing inductive effect $(+ I effect)$ of alkyl group increases the electron density on N atom and unshared pair of electrons on N atom can be easily donated.

Arrange the following in the increasing order of their pKb values : $C_{6} H_{5} {NH}_{2}, C_{2} H_{5} {NH}_{2}, C_{6} H_{5} {NHCH}_{3}$

Chapter-Wise 3D Chemistry Videos from Embibe Experts EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY

Physical Properties of Diazonium Salts

Alkylation and Acetylation of Amines

Comparison of Basicity of Aryl Amine and Ammonia

Learn and Prepare for any exam you want !

Arrange the following in the increasing order of their pKb values : C6H5NH2,C2H5NH2,C6H5NHCH3

Chapter-Wise 3D Chemistry Videos from Embibe Experts EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY

Physical Properties of Diazonium Salts

Alkylation and Acetylation of Amines

Comparison of Basicity of Aryl Amine and Ammonia

Learn and Prepare for any exam you want !

Arrange the following in the increasing order of their pKb values : $C_{6} H_{5} {NH}_{2}, C_{2} H_{5} {NH}_{2}, C_{6} H_{5} {NHCH}_{3}$