Amines

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (B) 

Hoffmann bromamide reaction- it is also called degradation reaction as in this reaction primary amide group is treated with halogen first (Br) then the halogen-substituted amide product is converted to a primary amine with the release of carbon dioxide gas.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (D)

Lithium aluminium hydride in ether is a strong reducing agent that donates its hydride ion to any C=O containing functional groups into corresponding reduced compounds. Here, the amide group is converted to an amine functional group.

LiAlH₄ in ether is the best reagent for converting 2-phenylpropanamide to 2-phenylpropanamine.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: ( C)

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (D)

Gabriel synthesis reaction:  

Gabriel's synthesis is a method for producing primary amines. When phthalimide is treated with ethanolic potassium hydroxide, it forms a potassium salt of phthalimide, which when heated with an alkyl halide and then alkaline hydrolyzed yields the corresponding primary amine. This method cannot produce aromatic primary amines because aryl halides do not undergo nucleophilic substitution with the anion formed by phthalimide.

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)