NEET Previous Year Questions (2014-21): Amines Notes | Study Chemistry Class 12 - NEET

Q.1. Identify the compound that will react with Hinsberg's reagent to give a solid which dissolves in alkali.    (2021)
A:
B:
C:
D:
Ans: A
Solution: 1° amines react with Hingsberg's reagent to give a solid, which dissolve in alkali.


Q.2. The reagent 'R' in the given sequence of a chemical reaction is :     (2021)

A: HI
B: CuCN/KCN
C: H₂O
D: CH₃CH₂OH
Ans: D
Solution:

R : CH3CH2OH
Certain mild reducing agents like hypophosphorus acid or ethanol reduce diazonium salts to arene and themselves get oxidised to phosphorous acid and ethanal respectively.

Q.3. Which of the following amine will give the carbylamine test?    (2020)  
A:

B:

C:

D:

Ans: C

Carbylamine reaction is give by 1° amine & aniline.

Q.4. The correct order of the basic strength of methyl substituted amines in aqueous solution is:    (2019)  
A: (CH₃)₂NH > CH₃NH₂ > (CH₃)₃N
B: (CH₃)₃N > CH₃NH₂ > (CH₃)₂NH
C: (CH₃)₃N > (CH₃)₂NH > CH₃NH₂
D: CH₃NH₂ > (CH₃)₂NH > (CH₃)₃N
Ans: A
Solution:
In aqueous solution, electron donating inductive effect, solvation effect (H-bonding) and steric hindrance all together affect basic strength of substituted amines
Basic character:


Q.5. Nitration of aniline in strong acidic medium also gives m-nitroaniline because     (2018)
A: In spite of substituents nitro group always goes to only m-position.
B: In electrophilic substitution reactions amino group is meta directive.
C: In absence of substituents nitro group always goes to m-position
D: In acidic (strong) medium aniline is present as anilinium ion.
Ans: D
Solution:

In acidic medium aniline is protonated to form anilinium ion which is metadirecting.

Q.6. Which of the following reactions is appropriate forconverting acetamide to methanamine ?    (2017)
A: Hoffmann hypobromamide reaction
B: Stephens reaction
C: Gabriels phthalimide synthesis
D: Carbylamine reaction
Ans: A
Solution:

This reaction is known as hoffmann hypobromamide reaction.

Q.7. The correct statement regarding the basicity of arylamines is :    (2016)
A: Arylamines are generally more basic than alkylamines, because the nitrogen atom in arylamines is sp-hybridized.
B: Arylamines are generally less basic than alkylamines because the nitrogen lone pair electrons are delocalized by interaction with the aromatic ring π electrons system.
C: Arylamines are generally more basic than alkylamines because the nitrogen lone pair electrons are not delocalized by interaction with the aromatic ring π electron system.
D: Arylamines are generally more basic than alkylamines because of aryl group
Ans: B
Solution:
In arylamines, lone pair of electrons on nitrogen atom is delocalised over the benzene ring, thus, not available for donation. So, arylamines are less basic than alkylamines.

Q.8. The electrolytic reduction of nitrobenzene in strongly acidic medium produces:    (2015)
A: Aniline
B: p-Aminophenol
C: Azoxybenzene
D: Azobenzene
Ans: B
Solution:
Electrolytic reduction of nitrobenzene in weakly acidic medium gives aniline but in strongly acidic medium, it gives para-amino phenol obviously through the acid catalysed rearrangement of initially formed phenyl hydroxyl amine.

Q.9. In the following reaction, the product (A)    (2014)