Organic Compounds Containing Nitrogen — Page 3 | NEET Chemistry

Q21

Nitrobenzene can be prepared from benzene by using a mixture of conc. HNO 3 and conc. H 2 SO 4 . In the mixture, nitric acid acts as a/an

A acid

B base

C catalyst

D reducing agent

Correct Answer

Option B

Solution

Nitric acid acts as a base by accepting a proton.

Q22

Which one of the following on reduction with lithium aluminium hydride yields a secondary amine?

A Methyl isocyanide

B Acetamide

C Methyl cyanide

D Nitroethane

Correct Answer

Option A

Solution

Reduction of alkyl isocyanides in presence of LiAlH 4 yields secondary amines containing methyl as one of the alkyl group.

Q23

Which of the following is more basic than aniline?

A Benzylamine

B Diphenylamine

C Triphenylamine

D

p

-Nitroaniline

Correct Answer

Option A

Solution

Benzylamine is more basic than aniline.

The reason is that in aniline, the lone pair of nitrogen is conjugated with benzene ring so it is not available readily for others.

On the other hand in Benzylamine, nitrogen is not directly attached with ring so lone pairs are not conjugated with ring.

Q24

Intermediates formed during reaction of are

A R CONHBr and R NCO

B R NHCOBr and R NCO

C R NH

-

Br and R CONHBr

D R CONBr 2

Correct Answer

Option A

Solution

The Hofmann bromamide reaction is as : RCONH 2 + Br 2 + KOH $\to$ RNH 2 The mechanism is as follows :

Q25

Ethyl isocyanide on hydrolysis in acidic medium generates

A propanoic acid and ammonium salt

B ethanoic acid and ammonium salt

C methylamine salt and ethanoic acid

D ethylamine salt and methanoic acid

Correct Answer

Option D

Solution

Ethyl isocyanide on hydrolysis form primary amines. Therefore it gives only one mono chloroalkane.

Q26

Which of the following amines can be prepared by Gabriel phthalimide reaction ?

A neo-pentylamine

B n-butylamine

C t-butylamine

D triethylamine

Correct Answer

Option B

Solution

Gabriel phthalimide synthesis is used to prepare 1o aliphatic amine.

Q27

Which of the following is least basic?

A

{(C{H_3}CO)_2}\mathop N\limits^{..} H

B

(C{H_3}CO)\mathop N\limits^{..} H{C_2}{H_5}

C

{({C_2}{H_5})_3}\mathop N\limits^{..}

D

{({C_2}{H_5})_2}\mathop N\limits^{..} H

Correct Answer

Option A

Solution

Basic strength $\propto$ availability of lone pair. In this case lone pair of

\mathop N\limits^{ \bullet \bullet }

is highly participating in resonance.

Q28

In the reaction of hypobromite with amide, the carbonyl carbon is lost as :

A CO2

B CO

C HCO

_3^ -

D CO

_3^{2 - }

Correct Answer

Option D

Solution

Carbonyl carbon is lost as

CO_3^{2 - }

.

Q29

Given below are two statements I and II. Statement I : Dumas method is used for estimation of "Nitrogen" in an organic compound. Statement II : Dumas method involves the formation of ammonium sulphate by heating the organic compound with conc

\mathrm{H}_2 \mathrm{SO}_4

. In the light of the above statements, choose the correct answer from the options given below

A Statement I is true but Statement II is false

B Statement I is false but Statement II is true

C Both Statement I and Statement II are true

D Both Statement I and Statement II are false

Correct Answer

Option A

Solution

In Dumas method nitrogen present in organic compound is converted into $\mathrm{N}_2$ gas whose volumetric analysis gives the percentage of nitrogen atom in the organic compound.

Q30

Which one of the following methods is neither meant for the synthesis nor for separation of amines?

A Hinsberg method

B Hofmann method

C Wurtz reaction

D Curtius reaction

Correct Answer

Option C

Solution

Wurtz reaction is for the preparation of hydrocarbons from alkyl halide

RX + 2Na + XR\overset{\,}\longrightarrow R - R + 2NaX