Organic Compounds Containing Nitrogen Questions — JEE Chemistry

Q1

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.

Q2

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.

Q3

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.

Q4

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 - }

.

Q5

A primary aliphatic amine on reaction with nitrous acid in cold (273 K) and there after raising temperature of reaction mixture to room temperature (298 K), gives a/an

A nitrile

B alcohol

C diazonium salt

D secondary amine

Correct Answer

Option B

Solution

$\mathrm{R}-\mathrm{NH}_2 \underset{+\mathrm{HCl}}{\stackrel{\mathrm{NaNO}_2}{\longrightarrow}} \mathrm{R}-\mathrm{N}_2^{+} \rightarrow \mathrm{R}^{+} \underset{\mathrm{H}_2 \mathrm{O}}{\longrightarrow} \mathrm{R}-\mathrm{OH}$

Q6

Given below are two statements: one is labelled as Assertion

\mathbf{A}

and the other is labelled as Reason

\mathbf{R}

Assertion A : Aniline on nitration yields ortho, meta & para nitro derivatives of aniline. Reason

\mathrm{R}

: Nitrating mixture is a strong acidic mixture. In the light of the above statements, choose the correct answer from the options given below

A Both A and R are true and R is the correct explanation of A

B Both

\mathrm{A}

and

\mathrm{R}

are true but

\mathrm{R}

is NOT the correct explanation of

\mathrm{A}

C A is true but R is false

D A is false but R is true

Correct Answer

Option A

Solution

Due to formation of anilinium ion in acidic medium meta product is also obtained in significant amount

Q7

An organic compound having molecular mass 60 is found to contain C = 20%, H = 6.67% and N = 46.67% while rest is oxygen. On heating it gives NH3 along with a solid residue. The solid residue give violet colour with alkaline copper sulphate solution. The compound is

A CH3NCO

B CH3CONH2

C (NH2)2CO

D CH3CH2CONH2

Correct Answer

Option C

Solution

Elements % Relative number of atoms Simple Ratio C 20% 20/12=1.66 1.66/1.66=1 H 6.67% 6.67/1=6.67 6.67/1.66=4.16 N 46.67% 46.67/14=3.33 3.33/1.66=2.02 O 26.64% 26.64/16=1.66 1.66/1.66=1.0 The compound is

C{H_4}{N_2}O

Empirical weight

=60;

Mol. wt.

=60;

$\therefore$

\,\,\,\,

n = {{60} \over {60}} = 1

On heating urea losses ammonia to give Biuret Biuret with alkaline

CuS{O_4}

gives violet colour. Test for

-CONH-

group.

Q8

A compound with molecular mass 180 is acylated with CH3COCl to get a compound with molecular mass 390. The number of amino groups present per molecule of the former compound is:

A 2

B 5

C 4

D 6

Correct Answer

Option B

Solution

Now since the molecular mass increases by

42

unit as a result of the reaction of one mole of

C{H_3}COCl

with one-

N{H_2}

group and the given increase in mass is

210.

hence the number of

- N{H_2}

group is

210/42=5

Q9

Given below are two statements : Statement (I) : All the following compounds react with p-toluenesulfonyl chloride.

\mathrm{C}_6 \mathrm{H}_5 \mathrm{NH}_2 \quad\left(\mathrm{C}_6 \mathrm{H}_5\right)_2 \mathrm{NH} \quad\left(\mathrm{C}_6 \mathrm{H}_5\right)_3 \mathrm{N}

Statement (II) : Their products in the above reaction are soluble is aqueous

\mathrm{NaOH}

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

A Statement I is false but Statement II is true

B Both Statement I and Statement II are true

C Both Statement I and Statement II are false

D Statement I is true but Statement II is false

Correct Answer

Option C

Solution

Let's analyze both statements one by one.

Statement (I): All the following compounds react with p-toluenesulfonyl chloride.

The compounds given are:

\mathrm{C}_6 \mathrm{H}_5 \mathrm{NH}_2 \quad (\mathrm{Aniline})

\left(\mathrm{C}_6 \mathrm{H}_5\right)_2 \mathrm{NH} \quad (\mathrm{Diphenylamine})

\left(\mathrm{C}_6 \mathrm{H}_5\right)_3 \mathrm{N} \quad (\mathrm{Triphenylamine})

P-toluenesulfonyl chloride (TsCl) reacts with amines to form sulfonamides. The general reaction is:

\mathrm{RNH}_2 + \mathrm{TsCl} \rightarrow \mathrm{RNHTs} + \mathrm{HCl}

For this reaction to occur, the amine must have at least one hydrogen attached to the nitrogen.

Let's check the provided compounds: 1.

\mathrm{C}_6 \mathrm{H}_5 \mathrm{NH}_2

(Aniline) - primary amine, has 2 hydrogens, so it reacts. 2.

\left(\mathrm{C}_6 \mathrm{H}_5\right)_2 \mathrm{NH}

(Diphenylamine) - secondary amine, has 1 hydrogen, so it reacts. 3.

\left(\mathrm{C}_6 \mathrm{H}_5\right)_3 \mathrm{N}

(Triphenylamine) - tertiary amine, has no hydrogen, so it does not react. Hence, Statement I is false, since

\left(\mathrm{C}_6 \mathrm{H}_5\right)_3 \mathrm{N}

does not react with p-toluenesulfonyl chloride.

Statement (II): Their products in the above reaction are soluble in aqueous

\mathrm{NaOH}

.

The products of the reaction of aniline and diphenylamine with p-toluenesulfonyl chloride (if it were to happen for the sake of analysis) would be sulfonamides:

\mathrm{RNH}_2 + \mathrm{TsCl} \rightarrow \mathrm{RNHTs}

Sulfonamides (RNHTs) are generally not soluble in aqueous NaOH because they are neutral compounds and NaOH is a strong base.

Only aniline itself is soluble in aqueous NaOH due to its basic nature, but its product with TsCl is not.

Thus, Statement II is also false, as the products would not be soluble in aqueous NaOH.

Conclusion: Both Statement I and Statement II are false.

Therefore, the correct answer is: Option C Both Statement I and Statement II are false.

Q10

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.