Chemistry Class 12 NCERT Solutions: Chapter 13 Amines Part 2

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Q: 4. Arrange the following in increasing order of their basic strength:

(i)

(ii)

(iii)

Answer:

(i) Considering the inductive effect of alkyl groups, can be arranged in the increasing order of their basic strengths as:

has proton acceptability less than . Thus, we have:

Due to the −I effect of group, the electron density on the N/atom in is lower than that on the N-atom in , but more than that in . Therefore, the given compounds can be arranged in the order of their basic strengths as:

(ii) Considering the inductive effect and the steric hindrance of the alkyl groups, , and their basic strengths as follows:

Again, due to the −R effect of group, the electron density on the N atom in is lower than that on the N atom in . Therefore, the basicity of is lower than that of . Hence, the given compounds can be arranged in the increasing order of their basic strengths as follows:

(iii) Considering the inductive effect and the steric hindrance of alkyl groups, , , and can be arranged in the increasing order of their basic strengths as:

In is directly attached to the benzene ring. Thus, the lone pair of electrons on the is delocalized over the benzene ring. In is not directly attached to the benzene ring. Thus, its lone pair is not delocalized over the benzene ring. Therefore, the electrons on the N atom are more easily available for protonation in than in i.e., is more basic than .

Again, due to the −I effect of group, the electron density on the atom in is lower than that on the N−atom in . Therefore, is more basic than . Thus, the given compounds can be arranged in the increasing order of their basic strengths as follows.

Q: 5. Complete the following acid-base reactions and name the products:

(i)

(ii)

Answer:

(i) >

(ii)

Q: 6. Write reactions of the final alkylation product of aniline with excess of methyl iodide in the presence of sodium carbonate solution.

Aniline reacts with methyl iodide to produce N, N-dimethylaniline.

Q 6 1 Structure of Aniline and N, N-Dimethylaniline

Q 6 1 Structure of Aniline and N, N-Dimethylaniline

Q 6 1 Structure of Aniline and N, N-Dimethylaniline

With excess methyl iodide, in the presence of solution, N, N-dimethylaniline produces N, N, N−trimethylanilinium carbonate.

Q 6 1 Structure N, N-Dimethylaniline N, N, N-Trimethylanilinium iodide N,N,N-Trimethylanilinium Carbonate

Q 6 1 N, N-Dimethylaniline N,N,N-Trimethylanilinium Carbonate

Q 6 1 Structure N, N-Dimethylaniline N, N, N-Trimethylanilinium iodide N,N,N-Trimethylanilinium Carbonate

Q: 7. Write chemical reaction of aniline with benzoyl chloride and write the name of the product obtained.

Answer:

Q 7 1 Aniline Benzoyl Chloride and N-Phenylbenzamide

Q 7 1 Aniline Benzoyl Chloride and N-Phenylbenzamide

Q 7 1 Aniline Benzoyl Chloride and N-Phenylbenzamide