Chemistry NCERT Exemplar Solutions Class 12th Chapter Thirteen

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (C) 

Potassium cyanide, as cyanide on reduction with sodium metal in alcohol, produces amine with increased carbon atoms. 

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (B)

Lithium aluminum hydride in ether is a strong reducing agent that donates its H? hydride ion to any C=O containing a functional group. In addition to LiAlH₄ to aryl nitro compounds, no reaction will be observed, the desired products of amines will not be produced, rather it will form diazobenzene products.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (C) 

S_N¹ reaction: A nucleophilic reaction that occurs in two steps, first is the bond-breaking step and the second is the production of the carbocation. The stability of carbocation formed in the second step determines the rate of reactivity of reactant toward S_N¹ reaction.  Here, C₆H₅CH₂Br,  

In the process of ionization, removal of bromine, a stable Benzyl carbocation is produced. Therefore, it is best suited for reaction through the S_N¹ mechanism. 

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans:  (A) 

The NH₂ group is directly attached to the benzene ring in aniline and other aryl amines. As a result, the unshared electron pair on the nitrogen atom is conjugated with the benzene ring, making it less available for protonation.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans:  (C)

Because of the electron-releasing nature of the alkyl group, it (R) pushes electrons towards nitrogen, making the unshared electron pair more available for sharing with the acid's proton. Furthermore, the +I effect of the alkyl group stabilizes the substituted ammonium ion formed from the amine by dispersing the positive charge.

As a result, alkylamines are more powerful bases than ammonia.

As a result, the basic nature of aliphatic amines should increase as the number of alkyl groups increases.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: Correct answer: (D) 

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (B) Triethylamine 

The structure of the given amines are shown below.