Amines

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option a and c

(a) Primary alkyl halides react with ammonia to give primary amines. Correct reaction.

(B) Elimination process doesn't occur with aq. KOH, hydrolysis process takes place. (B) is incorrect. 

(c) Dehydrohalogenation I.e. elimination of HCl occurs which produces alkene as the product takes place with alc. KOH . (c) is correct.

(d) In this reaction, aliphatic primary amines, on treatment with nitrous acid, produce primary alcohol as a product.

Therefore (d) is incorrect. 

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (a and b) 

Gabriel 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 is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: A, B & C  

As the NH₂ group is Ortho para directing group, so Br⁺ attacks only at the o and p positions thus the products formed corresponds to the option A, B and C.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: Option a and b

NHCOCH₃ is an ortho- para directing group so ortho-para products are formed. 

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (B and C) 

Certain mild reducing agents like hypophosphorous acid (phosphinic acid) or ethanol reduce diazonium salts to arenes and themselves get oxidised to phosphorous acid and ethanol, respectively.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (A and B)

When aliphatic and aromatic primary amines are heated with chloroform and ethanolic potassium hydroxide, they form isocyanides or carbylamines, which have a foul odor. This reaction does not occur in secondary or tertiary amines.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (A, B & C) 

Nitro compounds are reduced to amines by passing hydrogen gas through an acidic medium containing finely divided nickel, palladium, or platinum, as well as by reduction with metals in an acidic medium.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (C and D) 

Chlorobenzene and bromobenzene are prepared by the sandmeyer's reaction. 

While fluorobenzene and iodobenzene are prepared by simple heating of diazonium salt with aqueous KI Solution.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (D)

Aliphatic and arylalkyl primary amines can be prepared by the reduction of the corresponding nitriles with LiAlH₄

Heating alkyl halide with primary, secondary and tertiary amine can be prepared by reduction of LiAlH4 followed by treatment with water.

Heating alkyl halide with potassium salt of phthalimide followed by hydrolysis produces primary amine. This process is known as Gabriel phthalimide reaction. The number of carbon atoms in the chain of amines of product is same as reactant.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: (B)

Among primary, secondary, and tertiary amines, tertiary amines are the most volatile compounds as they don't have any strong intermolecular H-bonding between N-H like the primary and secondary amines have. 

So due to weak dipole-dipole interactions, (B) will be the most volatile.