Organic Chemistry: Some Basic Principles and Techniques

Q1 FREE PREVIEW

PYQ

In Friedel-Crafts alkylation of aniline, one gets: [JEE Main 2022, 29 Jun (Shift 2)]

aalkylated product with ortho and para substitution.

bsecondary amine after acidic treatment

can amide product.

dPositively charged nitrogen at benzene ring.

✓ Correct answer: d) Positively charged nitrogen at benzene ring.

ExplanationThe friedel-crafts alkylation of aniline occurs as: Aniline shows an acid-base reaction with the , a lewis acid. aniline is a Lewis base, while acts as a lewis acid.

Q2 FREE PREVIEW

PYQ

With respect to the compounds , choose the incorrect statement(s).

aThe acidity of compound is due to delocalization in the conjugate base.

bThe conjugate base of compound IV is aromatic.

cCompound II becomes more acidic, when it has a substituent.

dThe acidity of compounds follows the order I

✓ Correct answer: d) The acidity of compounds follows the order I

ExplanationOption D is incorrect because the given order of acidity is not accurate.The acidity of a compound depends on the stability of its conjugate base.In compound I, the conjugate base (carbanion) is highly stabilized by resonance over three benzene rings, making it the most acidic.Compound IV forms a conjugate base that is aromatic and thus gains extra stability, so it is also relatively acidic.Next comes compound V (a terminal alkyne), where the negative charge is stabilized due to the high s-character of the sp-hybridized carbon.Compound II (benzene) is much less acidic, and compound III (an alkane) is the least acidic.Therefore, the exact order given in option D is not correctly justified, making D the incorrect statement.

Q3 FREE PREVIEW

PYQ

In the given structure, number of sp and hybridized carbon atoms present respectively are : [JEE Main 2025, 24 Jan (Shift 2)]

a3 and 6

b4 and 6

c3 and 5

d4 and 5

✓ Correct answer: c) 3 and 5

Explanationsp and hybridized carbon atoms in the structure can be shown as: No. of sp hybridized carbon-3 No. of hybridized carbon-5

Q4 FREE PREVIEW

PYQ

Methyl group attached to a positively charged carbon atom stabilizes the carbocation due to [Re-NEET 2024]

a-I-effect

belectromeric effect

chyperconjugation

dmesomeric effect

✓ Correct answer: c) hyperconjugation

ExplanationIn hyperconjugation, the σ C–H bonds adjacent to the positively charged carbon overlap with the empty p-orbital, delocalizing the positive charge and stabilizing the carbocation.

Q5 FREE PREVIEW

PYQ

The correct stability order of carbocations is

[JEE Main 2024, 30 Jan (Shift 2)]

a

\({({\mathrm{CH}}_{3})}_{3}\overset{+}{\mathrm{C}}>{\mathrm{CH}}_{3}-\overset{+}{\mathrm{C}}{\mathrm{H}}_{2}>{({\mathrm{CH}}_{3})}_{2}\overset{+}{\mathrm{C}}\mathrm{H}>\overset{+}{\mathrm{C}}{\mathrm{H}}_{3}\)

b

\(\overset{+}{\mathrm{C}}{\mathrm{H}}_{3}>{\mathrm{CH}}_{3}-\overset{+}{\mathrm{C}}{\mathrm{H}}_{2}>{\mathrm{CH}}_{3}-\overset{+}{\mathrm{C}}\mathrm{H}>{\left({\mathrm{CH}}_{3}\right)}_{3}{\mathrm{C}}^{+}\\ |\\ {\mathrm{CH}}_{3}\)

c

\({({\mathrm{CH}}_{3})}_{3}\overset{+}{\mathrm{C}}>{({\mathrm{CH}}_{3})}_{2}\overset{+}{\mathrm{C}}\mathrm{H}>{\mathrm{CH}}_{3}-\overset{+}{\mathrm{C}}{\mathrm{H}}_{2}>\overset{+}{\mathrm{C}}{\mathrm{H}}_{3}\)

d

\(\overset{+}{\mathrm{C}}{\mathrm{H}}_{3}>{({\mathrm{CH}}_{3})}_{2}\overset{+}{\mathrm{C}}\mathrm{H}>{\mathrm{CH}}_{3}-\overset{+}{\mathrm{C}}{\mathrm{H}}_{2}>{\left({\mathrm{CH}}_{3}\right)}_{3}{\mathrm{C}}^{+}\)

✓ Correct answer: c)

\({({\mathrm{CH}}_{3})}_{3}\overset{+}{\mathrm{C}}>{({\mathrm{CH}}_{3})}_{2}\overset{+}{\mathrm{C}}\mathrm{H}>{\mathrm{CH}}_{3}-\overset{+}{\mathrm{C}}{\mathrm{H}}_{2}>\overset{+}{\mathrm{C}}{\mathrm{H}}_{3}\)

Explanation

More no. of hyperconjugable Hydrogens, more stable is the carbocation.

Q6 FREE PREVIEW

PYQ

CORRECT order of stability for the following is

\({\text{CH}}_{2}={\text{CH}}^{−},{\text{CH}}_{3}−{\text{CH}}_{2}^{−},\text{CH}\equiv {\text{C}}^{−}\)

[JEE Main 2026, 28 Jan (Shift 2)]

a

\(\mathrm{CH}\equiv {\mathrm{C}}^{−}>{\mathrm{CH}}_{2}={\mathrm{CH}}^{−}>{\mathrm{CH}}_{3}−{\mathrm{CH}}_{2}^{−}\)

b

\({\text{CH}}_{3}−{\text{CH}}_{2}^{−}>{\text{CH}}_{2}={\text{CH}}^{−}>\text{CH}\equiv {\text{C}}^{−}\)

c

\({\text{CH}}_{2}={\text{CH}}^{−}>\text{CH}\equiv {\text{C}}^{−}>{\text{CH}}_{3}−{\text{CH}}_{2}^{−}\)

d

\(\text{CH}\equiv {\text{C}}^{−}>{\text{CH}}_{3}−{\text{CH}}_{2}^{−}>{\text{CH}}_{2}={\text{CH}}^{−}\)

✓ Correct answer: a)

\(\mathrm{CH}\equiv {\mathrm{C}}^{−}>{\mathrm{CH}}_{2}={\mathrm{CH}}^{−}>{\mathrm{CH}}_{3}−{\mathrm{CH}}_{2}^{−}\)

Explanation

These are carbanions, so stability depends mainly on hybridization.

Rule: Greater s-character stabilizes the negative charge more.

sp → 50% s-character
sp² → 33% s-character
sp³ → 25% s-character

So:

CH≡C⁻ (sp) → most stable
CH₂=CH⁻ (sp²) → moderately stable
CH₃–CH₂⁻ (sp³) → least stable

Final order:

CH≡C⁻ > CH₂=CH⁻ > CH₃–CH₂⁻

Q7 FREE PREVIEW

PYQ

Given below are two statements :
Statement I : Hyperconjugation is not a permanent effect.
Statement II : In general, greater the number of alkyl groups attached to a positively charged C -atom, greater is the hyperconjugation interaction and stabilization of the cation.
In the light of the above statements, choose the correct answer from the options given below

[JEE Main 2025, 3 Apr (Shift 2)]

a

Statement I is true but Statement II is false

b

Both Statement I and Statement II are false

c

Statement I is false but Statement II is true

d

Both Statement I and Statement II are true

✓ Correct answer: c)

Statement I is false but Statement II is true

Explanation

Hyperconjugation is a permanent effect because no external reagent is required. Therefore, Statement I is false and Statement II is true.
More alkyl groups mean more α-hydrogen atoms, leading to greater hyperconjugation, which results in greater stability of the carbocation.

Q8 FREE PREVIEW

PYQ

Given below are two statements :
Statement (I) : In partition chromatography, stationary phase is thin film of liquid present in the inert support.
Statement (II) : In paper chromatography, the material of paper acts as a stationary phase. In the light of the above statements, choose the correct answer from the options given below :

[JEE Main 2025, 29 Jan (Shift 2)]

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 false

d

Both Statement I and Statement II are true

✓ Correct answer: a)

Statement I is true but Statement II is false

Explanation

In paper chromatography, a special quality paper known as chromatography paper is used. Chromatography paper contains water trapped in it, which acts as the stationary phase

Q9 FREE PREVIEW

PYQ

Appearance of blood red colour, on treatment of the sodium fusion extract of an organic compound with \(\mathrm{FeSO}_{4}\) in presence of concentrated \(\mathrm{H}_{2} \mathrm{SO}_{4}\) indicates the presence of element/s

[JEE Main 2024, 29 Jan (Shift 1)]

a

\(\mathrm{S}\)

b

\(\mathrm{N}\) and \(\mathrm{S}\)

c

\(\mathrm{Br}\)

d

\(\mathrm{N}\)

✓ Correct answer: b)

\(\mathrm{N}\) and \(\mathrm{S}\)

Explanation

\({\text{Fe}}^{2+}\overset{{\text{H}}^{+}}{\underset{\text{conc. }{\text{H}}_{2}{\text{SO}}_{4}}{\to }}{\text{Fe}}^{3+}\)

\({\text{Fe}}^{3+}+{\text{SCN}}^{−}\to {\text{Fe(SCN)}}_{3}\text{ }(\text{blood-red colour})\)

Appearance of blood-red colour confirms the presence of both nitrogen and sulphur.

Q10 FREE PREVIEW

PYQ

Appearance of blood red colour, on treatment of the sodium fusion extract of an organic compound with \(\mathrm{FeSO}_{4}\) in presence of concentrated \(\mathrm{H}_{2} \mathrm{SO}_{4}\) indicates the presence of element/s

[JEE Main 2024, 29 Jan (Shift 1)]

a

\(\mathrm{S}\)

b

\(\mathrm{N}\) and \(\mathrm{S}\)

c

\(\mathrm{Br}\)

d

\(\mathrm{N}\)

✓ Correct answer: b)

\(\mathrm{N}\) and \(\mathrm{S}\)

Explanation

\({\text{Fe}}^{2+}\overset{{\text{H}}^{+}}{\underset{\text{conc. }{\text{H}}_{2}{\text{SO}}_{4}}{\to }}{\text{Fe}}^{3+}\)

\({\text{Fe}}^{3+}+{\text{SCN}}^{−}\to {\text{Fe(SCN)}}_{3}\text{ }(\text{blood-red colour})\)

Appearance of blood-red colour confirms the presence of both nitrogen and sulphur.

Q11 FREE PREVIEW

PYQ

In Dumas’ method for estimation of nitrogen \(0.4\mathrm{g}\) of an organic compound gave \(60\mathrm{mL}\) of nitrogen collected at \(300\mathrm{K}\) temperature and \(715\mathrm{mm}\) Hg pressure. The percentage composition of nitrogen in the compound is
(Given : Aqueous tension at \(300\mathrm{K}=15\mathrm{mm}\mathrm{Hg}\))

[JEE Main 2025, 3 Apr (Shift 2)]

a

\(15.71\%\)

b

\(20.95\%\)

c

\(17.46\%\)

d

\(7.85\%\)

✓ Correct answer: a)

\(15.71\%\)

Explanation

Pressure of N₂ gas evolved

\(=715−15=700\text{ mm Hg}\) \(=\frac{700}{760}\text{ atm}\)

Moles of N₂ evolved:

\(n=\frac{PV}{RT}\) \(=\frac{700\times 60\times {10}^{−3}}{760\times 0.0821\times 300}\) \(=0.0022\text{ mol}\)

Mass of N₂ evolved:

\(=0.0022\times 28=0.063\text{ g}\)

Weight percentage of nitrogen in the compound:

\(\mathrm{\%}N=\frac{\text{wt. of nitrogen}}{\text{wt. of compound}}\times 100\)% \(=\frac{0.063}{0.4}\times 100\) = 15.71%

Q12

PYQ

The incorrect statement regarding conformations of ethane is:

a

Ethane has infinite number of conformations

b

The dihedral angle in staggered conformation is 60°

c

Eclipsed conformation is the most stable conformation.

d

The conformations of ethane are interconvertible to one-another.

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Q13

PYQ

In 3,3-dimethylhex-1-ene-4-yne, there are _______ \({\mathrm{sp}}^{3}\), _______ \({\mathrm{sp}}^{2}\) and ______ sp hybridised carbon atoms respectively

[JEE Main 2025, 2 Apr (Shift 2)]

a

4, 2, 2

b

3, 3, 2

c

2, 4, 2

d

2, 2, 4

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Q14

PYQ

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 \({H}_{2}S{O}_{4}\)

[JEE Main 2025, 24 Jan (Shift 1)]

a

Statement I is false but Statement II is true

b

Statement I is true but Statement II is false

c

Both Statement I and Statement II are false

d

Both Statement I and Statement II are true

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Q15

PYQ

Which of the following nitrogen containing compound does not give Lassaigne's test?

[JEE Main 2024, 04 Apr (Shift 1)]

a

Glycine

b

Hydrazine

c

Phenyl hydrazine

d

Urea

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Q16

PYQ

Which of the following nitrogen containing compound does not give Lassaigne's test?

[JEE Main 2024, 04 Apr (Shift 1)]

a

Glycine

b

Hydrazine

c

Phenyl hydrazine

d

Urea

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Q17

PYQ

500 J of energy is transferred as heat to 0.5 mol of Argon gas at 298 K and 1.00 atm . The final temperature and the change in internal energy respectively are :
(Given : \(\mathrm{R}=8.3{\mathrm{JK}}^{-1}{\mathrm{mol}}^{-1}\))

a

378 K and 300 J

b

348 K and 300 J

c

368 K and 500 J

d

378 K and 500 J

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Q18

PYQ

Given below are two statements:
Statement I: In Lassaigne's test, the covalent organic molecules are transformed into ionic compounds.
Statement II: The sodium fusion extract of an organic compound having N and S gives Prussian blue colour with \({\mathrm{FeSO}}_{4}\mathrm{and}{\mathrm{Na}}_{4}\left[\mathrm{Fe}{(\mathrm{CN})}_{6}\right]\)

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

[JEE Main 2025, 23 Jan (Shift 1)]

a

Statement I is false but Statement II is true

b

Both Statement I and Statement II are false

c

Both Statement I and Statement II are true

d

Statement I is true but Statement II is false

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Q19

PYQ

In Kjeldahl's method for estimation of nitrogen, CuSO₄ acts as:

a

reducing agent

b

catalytic agent

c

oxidizing agent

d

hydrolysis agent

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Q20

PYQ

Given below are two statements :

Statement (I): Nitrogen, sulphur, halogen and phosphorus present in an organic compound are detected by Lassaigne's Test.

Statement (II) : The elements present in the compound are converted from covalent form into ionic form by fusing the compound with Magnesium in Lassaigne's test.

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

[JEE Main 2025, 22 Jan (Shift 2)]

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

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Q21

PYQ

In Dumas method for estimation of nitrogen, \(0.5\) gram of an organic compound gave \(60\) mL of nitrogen collected at \(300\) K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the compound (Aqueous tension at \(300\mathrm{K}=15\mathrm{mmHg}\)) is

[JEE Main 2025, 2 Apr (Shift 2)]

a

\(1.257\)

b

\(20.87\)

c

\(18.67\)

d

\(12.57\)

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Q22

PYQ

Given below are two statements:

Statement I: \({({\mathrm{CH}}_{3})}_{3}\overset{⊕}{\mathrm{C}}\) is more stable than \(\mathrm{C}{\mathrm{H}}_{3}\overset{⊕}{\mathrm{C}}\) as nine hyperconjugation interactions are possible in \({({\mathrm{CH}}_{3})}_{3}\overset{⊕}{\mathrm{C}}\).

Statement II: \(\overset{⊕}{{\mathrm{CH}}_{3}}\) is less stable than \({({\mathrm{CH}}_{3})}_{3}\overset{⊕}{\mathrm{C}}\) as only three hyperconjugation interactions are possible in \(\overset{⊕}{{\mathrm{CH}}_{3}}\).

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

[JEE Main 2026, 23 Jan (Shift 2)]

a

Statement I is false but Statement II is true

b

Both Statement I and Statement II are false

c

Statement I is true but Statement II is false

d

Both Statement I and Statement II are true

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Q23

PYQ

Identify correct statement/s :

(A) \(-OC{H}_{3}\) and \(-NHCOC{H}_{3}\) are activating group.
(B) \(-\)CN and \(-\)OH are meta directing group.
(C) \(-\)CN and \(-S{O}_{3}H\) are meta directing group.
(D) Activating groups act as ortho - and para directing groups.
(E) Halides are activating groups.

Choose the correct answer from the options given below :

[JEE Main 2025, 24 Jan (Shift 2)]

a

(A), (C) and (D) only

b

(A) and (C) only

c

(A) only

d

(A), (B) and (E) only

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Q24

PYQ

Chromatographic technique/s based on the principle of differential adsorption is/are

A. Column chromatography

B. Thin layer chromatography

C. Paper chromatography

Choose the most appropriate answer from the options given below:

[JEE Main 2024, 29 Jan (Shift 2)]

a

A only

b

B only

c

A & B only

d

C only

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Q25

PYQ

Chromatographic technique/s based on the principle of differential adsorption is/are

A. Column chromatography

B. Thin layer chromatography

C. Paper chromatography

Choose the most appropriate answer from the options given below:

[JEE Main 2024, 29 Jan (Shift 2)]

a

A only

b

B only

c

A & B only

d

C only

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Q26

PYQ

Given below are two statements. Select the correct option (JEE mains memory based shift-2 22/01/2025)

statement-1: Lassaigne test is used for detection of nitrogen, phosphorus, sulphur and halogens

statement-2: Lassaigne extract is made with magnesium metal

a

Both statement-1 and statement-2 are correct

b

Both statement-1 and statement-2 are incorrect

c

Statement-1 is correct, statement-2 is incorrect

d

Statement-1 is incorrect, statement-2 is correct

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Q27

PYQ

Chromatographic technique/s based on the principle of differential adsorption is/are

A. Column chromatography

B. Thin layer chromatography

C. Paper chromatography

Choose the most appropriate answer from the options given below:

a

A only

b

B only

c

A & B only

d

C only

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Q28

PYQ

When 1 g of compound (X) is subjected to Kjeldahl’s method for estimation of nitrogen, 15 mL 1 M H₂SO₄ was neutralized by ammonia evolved. The percentage of nitrogen in compound (X) is:

a

42

b

0.21

c

21

d

0.42

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Q29

PYQ

In the sulphur estimation, 0.20 g of a pure organic compound gave 0.40 g of barium sulphate. The percentage of sulphur in the compound is ________ \(\times {10}^{-1}\%\). [Nearest integer] (Molar mass : \(O=16,S=32,Ba=137\) in \(gmo{l}^{-1}\))

[JEE Main 2025, 29 Jan (Shift 2)]

a

275

b

375

c

475

d

575

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Q30

PYQ

During "S" estimation, 160 mg of an organic compound gives 466 mg of barium sulfate. The percentage of Sulphur in the given compound is ___________%

(Given molar mass in g/mol of Ba : 137 , S : 32, O : 16)

[JEE Main 2025, 23 Jan (Shift 1)]

a

50

b

60

c

40

d

70

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Q31

PYQ

In Dumas’ method for estimation of nitrogen \(0.4\mathrm{g}\) of an organic compound gave \(60\mathrm{mL}\) of nitrogen collected at \(300\mathrm{K}\) temperature and \(715\mathrm{mm}\) Hg pressure. The percentage composition of nitrogen in the compound is
(Given : Aqueous tension at \(300\mathrm{K}=15\mathrm{mm}\mathrm{Hg}\))

[JEE Main 2025, 3 Apr (Shift 2)]

a

\(15.71\%\)

b

\(20.95\%\)

c

\(17.46\%\)

d

\(7.85\%\)

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Q32

PYQ

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 \({H}_{2}S{O}_{4}\)

[JEE Main 2025, 24 Jan (Shift 1)]

a

Statement I is false but Statement II is true

b

Statement I is true but Statement II is false

c

Both Statement I and Statement II are false

d

Both Statement I and Statement II are true

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Q33

PYQ

The interaction between \(\pi\) bond and lone pair of electrons present on an adjacent atom is responsible for

[JEE Main 2024, 29 Jan (Shift 1)]

a

Resonance effect

b

Hyperconjugation

c

Inductive effect

d

Electromeric effect

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Q34

PYQ

The purification method based on the following physical transformation is :

\(\underset{(X)}{\text{ Solid }}\overset{\text{ Heat }}{\to }\underset{(X)}{\text{ Vapour }}\overset{\text{ Cool }}{\to }\underset{(X)}{\text{ Solid }}\)

[JEE Main 2025, 28 Jan (Shift 2)]

a

Sublimation

b

Crystallization

c

Extraction

d

Distillation

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Q35

PYQ

The technique used for purification of steam volatile water immiscible substance is:

a

Fractional distillation

b

Distillation

c

Fractional distillation under reduced pressure

d

Steam distillation

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Q36

PYQ

Which among the following purification methods is based on the principle of "Solubility" in two different solvents?

[JEE Main 2024, 30 Jan (Shift 2)]

a

Sublimation

b

Distillation

c

Differential Extraction

d

Column Chromatography

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Q37

PYQ

The interaction between \(\pi\) bond and lone pair of electrons present on an adjacent atom is responsible for

[JEE Main 2024, 29 Jan (Shift 1)]

a

Resonance effect

b

Hyperconjugation

c

Inductive effect

d

Electromeric effect

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Q38

PYQ

Match the Column

	Column-I (Compounds)		Column-II (pK_a value)
(I)	Phenol	(P)	15.9
(II)	Ethanol	(Q)	10
(III)	p-Nitrophenol	(R)	8.3
(IV)	m-Nitrophenol	(S)	7.1

Choose the correct answer from the options given below:

[JEE Main 2024, 29 Jan (Shift 2)]

a

I-Q, II-P, III-S, IV-R

b

I-S, II-R, III-Q, IV-P

c

I-P, II-Q, III-R, IV-S

d

I-Q, II-P, III-R, IV-S

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Q39

PYQ

Mixture of 1 g each of chlorobenzene, aniline and benzoic acid is dissolved in 50 mL ethyl acetate and placed in a separating funnel, 5 M NaOH ( 30 mL ) was added in the same funnel. The funnel was shaken vigorously and then kept aside. The ethyl acetate layer in the funnel contains

[JEE Main 2025, 7 Apr (Shift 2)]

a

benzoic acid

b

benzoic acid and aniline

c

benzoic acid and chlorobenzene

d

chlorobenzene and aniline

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Q40

PYQ

In Dumas’ method for estimation of nitrogen 1g of an organic compound gave 150 mL of nitrogen collected at 300K temperature and 900 mm Hg pressure. The percentage composition of nitrogen in the compound is _____ % (nearest integer). (Aqueous tension at 300 K = 15mm Hg)

[JEE Main 2025, 4 Apr (Shift 1)]

a

20

b

40

c

10

d

15

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Q41

PYQ

The purification method based on the following physical transformation is :

\(\underset{(X)}{\text{ Solid }}\overset{\text{ Heat }}{\to }\underset{(X)}{\text{ Vapour }}\overset{\text{ Cool }}{\to }\underset{(X)}{\text{ Solid }}\)

[JEE Main 2025, 28 Jan (Shift 2)]

a

Sublimation

b

Crystallization

c

Extraction

d

Distillation

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Q42

PYQ

The fragrance of flowers is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapour phase. A suitable method for the extraction of these oils from the flowers is

[JEE Main 2024, 31 Jan (Shift 2)]

a

Distillation

b

Crystallisation

c

Distillation under reduced pressure

d

Steam distillation

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Q43

PYQ

In Dumas method for estimation of nitrogen, \(0.5\) gram of an organic compound gave \(60\) mL of nitrogen collected at \(300\) K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the compound (Aqueous tension at \(300\mathrm{K}=15\mathrm{mmHg}\)) is

[JEE Main 2025, 2 Apr (Shift 2)]

a

\(1.257\)

b

\(20.87\)

c

\(18.67\)

d

\(12.57\)

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Q44

PYQ

In Dumas' method \(292\) mg of an organic compound released \(50\) mL of nitrogen gas \(\left({\mathrm{N}}_{2}\right)\)at 300 K temperature and \(715\) mm Hg pressure. The percentage composition of ' N ' in the organic compound is ________% (Nearest integer)
(Aqueous tension at \(300\mathrm{K}=15\mathrm{mmHg}\) )

[JEE Main 2025, 7 Apr (Shift 2)]

a

16

b

17

c

8

d

18

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Q45

PYQ

Which of the following form most stable carbocation?

Memory Based Question 29/Jan/25 Evening shift

a

\({\left(\mathrm{Ph}\right)}_{3}C-\mathrm{Br}\)

b

\({\text{C}}_{6}{H}_{5}C{\mathrm{H}}_{2}\mathrm{Br}\)

c

\({\text{C}}_{6}{H}_{5}C\mathrm{H}(\mathrm{Br}){\mathrm{CH}}_{3}\)

d

\(\text{C}{H}_{3}C{\mathrm{H}}_{2}C{\mathrm{H}}_{2}{\mathrm{CH}}_{2}\mathrm{Br}\)

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Q46

PYQ

Cyclohexene is __________ type of an organic compound?

[JEE Main 2024, 27 Jan (Shift 1)]

a

Alicyclic

b

Acyclic

c

Benzenoid non-aromatic

d

Benzenoid aromatic

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Q47

PYQ

Identify correct statement/s :

(A) \(-OC{H}_{3}\) and \(-NHCOC{H}_{3}\) are activating group.
(B) - CN and - OH are meta directing group.
(C) - CN and \(-S{O}_{3}H\) are meta directing group.
(D) Activating groups act as ortho - and para directing groups.
(E) Halides are activating groups.

Choose the correct answer from the options given below :

[JEE Main 2025, 24 Jan (Shift 2)]

a

(A), (C) and (D) only

b

(A) and (C) only

c

(A) only

d

(A), (B) and (E) only

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Q48

PYQ

The correct statement among the following, for a "chromatography" purification method is

[JEE Main 2024, 06 Apr (Shift 2)]

a

Non-polar compounds are retained at top and polar compounds come down in column chromatography.

b

Organic compounds run faster than solvent in the thin layer chromatographic plate.

c

\(R _f\) of a polar compound is smaller than that of a non-polar compound.

d

\(R_f\) is an integral value.

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Q49

PYQ

The correct statement among the following, for a "chromatography" purification method is

[JEE Main 2024, 06 Apr (Shift 2)]

a

Non-polar compounds are retained at top and polar compounds come down in column chromatography.

b

Organic compounds run faster than solvent in the thin layer chromatographic plate.

c

\(R _f\) of a polar compound is smaller than that of a non-polar compound.

d

\(R_f\) is an integral value.

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Q50

PYQ

Correct order of acidic strength will be

(i) n-butanol

(ii) 4-nitrophenol

(iii) 2,4-dinitrophenol

(iv) phenol

(Memory Based JEE Mains 22/01/2025 ,Shift -1)

a

(iii) > (ii) > (iv) > (i)

b

(iv) > (ii) > (iii) > (i)

c

(i) > (ii) > (iv) > (iii)

d

(ii) > (iii) > (iv) > (i)

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Q51

PYQ

The adsorbent used in adsorption chromatography is/are -
A. silica gel
B. alumina
C. quick lime
D. magnesia

Choose the most appropriate answer from the options given below :

a

C and D only

b

A only

c

A and B only

d

B only

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Q52

PYQ

Assertion (A): IUPAC name of \(HO - CH _2-\left( CH _2\right)_3- CH _2- COCH _3\) is 7-hydroxyheptan-2-one
Reason (R): 2 -oxoheptan-7-ol is the correct IUPAC name for above compound

In the light of the above statements, choose the most appropriate answer from the options given below

a

Assertion is correct but reason is incorrect.

b

Assertion is incorrect but reason is correct.

c

Both Assertion and reason are incorrect.

d

Both Assertion and reason are correct.

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Q53

PYQ

How many of the following can act as nucleophile? (memory based jee mains shift-1 29/01/2025)

\(\mathrm{Ph}-\mathrm{SH},{\mathrm{OH}}^{-},{\mathrm{CH}}_{2}={\mathrm{CH}}_{2},{\left({\mathrm{CH}}_{3}\right)}_{2}\mathrm{C}=\mathrm{N}-{\mathrm{CH}}_{3}\\ {\mathrm{H}}_{3}{\mathrm{O}}^{+},{\mathrm{CH}}_{3}{\mathrm{COCH}}_{3},{\mathrm{CH}}_{3}-\mathrm{S}-{\mathrm{CH}}_{3}\)

a

5

b

6

c

4

d

7

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Q54

PYQ

The adsorbent used in adsorption chromatography is/are -
A. silica gel
B. alumina
C. quick lime
D. magnesia

Choose the most appropriate answer from the options given below :

a

C and D only

b

A only

c

A and B only

d

B only

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Q55

PYQ

Consider the given statements and select the correct option (memory based jee mains shift-2 29/01/2025)

Statement-1: In partition chromatography, a thin film of liquid acts as stationary phase

Statement-2: Paper chromatography is not a type of partition chromatography

a

Statement-1 is correct, statement-2 is incorrect

b

Statement-1 is incorrect, statement-2 is correct

c

Statement-1 and statement-2 both are incorrect

d

Statement-1 and statement-2 both are correct

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Q56

PYQ

Mixture of 1 g each of chlorobenzene, aniline and benzoic acid is dissolved in 50 mL ethyl acetate and placed in a separating funnel, 5 M NaOH ( 30 mL ) was added in the same funnel. The funnel was shaken vigorously and then kept aside. The ethyl acetate layer in the funnel contains

[JEE Main 2025, 7 Apr (Shift 2)]

a

benzoic acid

b

benzoic acid and aniline

c

benzoic acid and chlorobenzene

d

chlorobenzene and aniline

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Q57

PYQ

In Carius method for estimation of halogens, 180 mg of an organic compound produced 143.5 mg of AgCl . The percentage composition of chlorine in the compound is ______ %.

(Given : molar mass in \(gmo{l}^{-1}\) of Ag : 108, Cl : 35.5 )

[JEE Main 2025, 22 Jan (Shift 1)]

a

20

b

40

c

60

d

80

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Q58

PYQ

Given below are two statements:
Statement I: In Lassaigne's test, the covalent organic molecules are transformed into ionic compounds.
Statement II: The sodium fusion extract of an organic compound having N and S gives Prussian blue colour with \({\mathrm{FeSO}}_{4}\mathrm{and}{\mathrm{Na}}_{4}\left[\mathrm{Fe}{(\mathrm{CN})}_{6}\right]\)

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

[JEE Main 2025, 23 Jan (Shift 1)]

a

Statement I is false but Statement II is true

b

Both Statement I and Statement II are false

c

Both Statement I and Statement II are true

d

Statement I is true but Statement II is false

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Q59

PYQ

The molecular formula of second homologue in the homologous series of monocarboxylic acids is

[JEE Main 2024, 27 Jan (Shift 2)]

a

\(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O}_{2}\)

b

\(\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{2}\)

c

\(\mathrm{C}_{2} \mathrm{H}_{2} \mathrm{O}_{2}\)

d

\(\mathrm{CH}_{2} \mathrm{O}\)

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Q60

PYQ

The molecular formula of second homologue in the homologous series of monocarboxylic acids is

[JEE Main 2024, 27 Jan (Shift 2)]

a

\(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O}_{2}\)

b

\(\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{2}\)

c

\(\mathrm{C}_{2} \mathrm{H}_{2} \mathrm{O}_{2}\)

d

\(\mathrm{CH}_{2} \mathrm{O}\)

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Q61

PYQ

Find out the statements which are not true.

A.Resonating structures with more number of covalent bonds and lesser charge separation are more stable.

B. In electromeric effect, an unsaturated system shows +E effect with nucleophile and -E effect with electrophile.

C. Inductive effect is responsible for high melting point, boiling point and dipole moment of polar compounds.

D. The greater the number of alkyl groups attached to the doubly bonded carbon atoms, higher is the heat of hydrogenation.

E. Stability of carbanion increases with the increase in s character of the carbon carrying the negative charge.

Choose the correct answer from the options given below:

a

A, C and D only

b

A, D & E only

c

B & D only

d

B, D & E only

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Q62

PYQ

In Dumas’ method for estimation of nitrogen \(0.4\mathrm{g}\) of an organic compound gave \(60\mathrm{mL}\) of nitrogen collected at \(300\mathrm{K}\) temperature and \(715\mathrm{mm}\) Hg pressure. The percentage composition of nitrogen in the compound is
(Given : Aqueous tension at \(300\mathrm{K}=15\mathrm{mm}\mathrm{Hg}\))

[JEE Main 2025, 3 Apr (Shift 2)]

a

\(15.71\%\)

b

\(20.95\%\)

c

\(17.46\%\)

d

\(7.85\%\)

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Q63

PYQ

CORRECT order of stability for the following is

\({\text{CH}}_{2}={\text{CH}}^{−},{\text{CH}}_{3}−{\text{CH}}_{2}^{−},\text{CH}\equiv {\text{C}}^{−}\)

[JEE Main 2026, 28 Jan (Shift 2)]

a

\(\mathrm{CH}\equiv {\mathrm{C}}^{−}>{\mathrm{CH}}_{2}={\mathrm{CH}}^{−}>{\mathrm{CH}}_{3}−{\mathrm{CH}}_{2}^{−}\)

b

\({\text{CH}}_{3}−{\text{CH}}_{2}^{−}>{\text{CH}}_{2}={\text{CH}}^{−}>\text{CH}\equiv {\text{C}}^{−}\)

c

\({\text{CH}}_{2}={\text{CH}}^{−}>\text{CH}\equiv {\text{C}}^{−}>{\text{CH}}_{3}−{\text{CH}}_{2}^{−}\)

d

\(\text{CH}\equiv {\text{C}}^{−}>{\text{CH}}_{3}−{\text{CH}}_{2}^{−}>{\text{CH}}_{2}={\text{CH}}^{−}\)

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Q64

PYQ

Which of the following form most stable carbocation?

Memory Based Question 29/Jan/25 Evening shift

a

\({\left(\mathrm{Ph}\right)}_{3}C-\mathrm{Br}\)

b

\({\text{C}}_{6}{H}_{5}C{\mathrm{H}}_{2}\mathrm{Br}\)

c

\({\text{C}}_{6}{H}_{5}C\mathrm{H}(\mathrm{Br}){\mathrm{CH}}_{3}\)

d

\(\text{C}{H}_{3}C{\mathrm{H}}_{2}C{\mathrm{H}}_{2}{\mathrm{CH}}_{2}\mathrm{Br}\)

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Q65

PYQ

Find out the statements which are not true.

A. Resonating structures with more number of covalent bonds and lesser charge separation are more stable.

B. In electromeric effect, an unsaturated system shows +E effect with nucleophile and -E effect with electrophile.

C. Inductive effect is responsible for high melting point, boiling point and dipole moment of polar compounds.

D. The greater the number of alkyl groups attached to the doubly bonded carbon atoms, higher is the heat of hydrogenation.

E. Stability of carbanion increases with the increase in s character of the carbon carrying the negative charge. Choose the correct answer from the options given below:

[JEE Main 2026, 24 Jan (Shift 2)]

a

A, C and D only

b

A, D & E only

c

B & D only

d

B, D & E only

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Q66

PYQ

\(\\ \mathrm{COOH}{\mathrm{COOCH}}_{3}\\ {\mathrm{CH}}_{3}-\overset{|}{\mathrm{C}}\mathrm{H}-{\mathrm{CH}}_{2}-\overset{|}{\mathrm{C}}\mathrm{H}-{\mathrm{CH}}_{3}\)

The IUPAC name is ?

(Shift - I Memory Based JEE Mains 22/01/2025)

a

4-methoxycarboxy-2-methylpentanoic acid

b

3-methoxycarboxy-2-methylpentanoic acid

c

5-methoxycarboxy-2-methylpentanoic acid

d

2-methoxycarboxy-3-methylpentanoic acid

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Q67

PYQ

500 J of energy is transferred as heat to 0.5 mol of Argon gas at 298 K and 1.00 atm . The final temperature and the change in internal energy respectively are :
(Given : \(\mathrm{R}=8.3{\mathrm{JK}}^{-1}{\mathrm{mol}}^{-1}\))

a

378 K and 300 J

b

348 K and 300 J

c

368 K and 500 J

d

378 K and 500 J

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Q68

PYQ

The set of meta directing functional groups from the following sets is:EndFragment

[JEE Main 2024, 01 Feb (Shift 2)]

a

\({\mathrm{NO}}_{2},−\mathrm{CHO},\text{ }−\text{ }{\mathrm{SO}}_{3}\mathrm{H},−\mathrm{COR}\)

b

\(CN,−\mathrm{CHO},\text{ }−\text{ }{\mathrm{NHCOCH}}_{3},\text{ }−\text{ }\mathrm{COOR}\)

c

\({\mathrm{NO}}_{2},\text{ }−\text{ }{\mathrm{NH}}_{2},\text{ }−\text{ }\mathrm{COOH},\text{ }−\text{ }\mathrm{COOR}\)

d

\(\mathrm{CN},\text{ }−\text{ }{\mathrm{NH}}_{2},\text{ }−\text{ }\mathrm{NHR},\text{ }−{\mathrm{OCH}}_{3}\)

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Q69

PYQ

When 1 g of compound (X) is subjected to Kjeldahl’s method for estimation of nitrogen, 15 mL 1 M H₂SO₄ was neutralized by ammonia evolved. The percentage of nitrogen in compound (X) is:

a

42

b

0.21

c

21

d

0.42

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Q70

PYQ

Given below are two statements :

Statement (I): Nitrogen, sulphur, halogen and phosphorus present in an organic compound are detected by Lassaigne's Test.

Statement (II) : The elements present in the compound are converted from covalent form into ionic form by fusing the compound with Magnesium in Lassaigne's test.

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

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Q71

PYQ

In 3,3-dimethylhex-1-ene-4-yne, there are _______ \({\mathrm{sp}}^{3}\), _______ \({\mathrm{sp}}^{2}\) and ______ sp hybridised carbon atoms respectively

[JEE Main 2025, 2 Apr (Shift 2)]

a

4, 2, 2

b

3, 3, 2

c

2, 4, 2

d

2, 2, 4

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Q72

PYQ

The monomer (X) involved in the synthesis of Nylon 6,6 gives positive carbylamine test. If 10 moles of \(\mathbf{X}\) are analyzed using Dumas method, the amount (in grams) of nitrogen gas evolved is

Use: Atomic mass of N (in amu) = 14

a

280

b

230

c

245

d

260

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Q73

PYQ

The technique used for purification of steam volatile water immiscible substance is

a

Fractional distillation

b

Distillation

c

Fractional distillation under reduced pressure

d

Steam distillation

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Q74

PYQ

The technique used for purification of steam volatile water immiscible substance is

a

Fractional distillation

b

Distillation

c

Fractional distillation under reduced pressure

d

Steam distillation

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Q75

PYQ

Given below are two statements:

Statement I: \({({\mathrm{CH}}_{3})}_{3}\overset{⊕}{\mathrm{C}}\) is more stable than \(\mathrm{C}{\mathrm{H}}_{3}\overset{⊕}{\mathrm{C}}\) as nine hyperconjugation interactions are possible in \({({\mathrm{CH}}_{3})}_{3}\overset{⊕}{\mathrm{C}}\).

Statement II: \(\overset{⊕}{{\mathrm{CH}}_{3}}\) is less stable than \({({\mathrm{CH}}_{3})}_{3}\overset{⊕}{\mathrm{C}}\) as only three hyperconjugation interactions are possible in \(\overset{⊕}{{\mathrm{CH}}_{3}}\).

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

a

Statement I is false but Statement II is true

b

Both Statement I and Statement II are false

c

Statement I is true but Statement II is false

d

Both Statement I and Statement II are true

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Q76

PYQ

Which among the following is incorrect statement ?

[JEE Main 2024, 4 Apr (Shift 1)]

a

Electromeric effect dominates over inductive effect

b

The electromeric effect is, temporary effect

c

The organic compound shows electromeric effect in the presence of the reagent only.

d

Hydrogen ion \(\left({H}^{+}\right)\)shows negative electromeric effect

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Q77

PYQ

Which among the following is incorrect statement ?

[JEE Main 2024, 4 Apr (Shift 1)]

a

Electromeric effect dominates over inductive effect

b

The electromeric effect is, temporary effect

c

The organic compound shows electromeric effect in the presence of the reagent only.

d

Hydrogen ion \(\left({H}^{+}\right)\)shows negative electromeric effect

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Q78

PYQ

In Carius method of estimation of halogen, 0.25 g of an organic compound gave 0.15 g of silver bromide (AgBr). The percentage of Bromine in the organic compound is______ \(\times {10}^{-1}\%\) (Nearest integer). (Given : Molar mass of Ag is 108 and Br is \(80gmo{l}^{-1}\) )

[JEE Main 2025, 24 Jan (Shift 2)]

a

255

b

265

c

275

d

285

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Q79

PYQ

What is the correct order of stability? (memory based jee mains shift-1 28/01/2025)

\(\left(\mathrm{I}\right){\mathrm{Ph}}_{3}{\mathrm{C}}^{+}\\ \left(\mathrm{II}\right){\mathrm{Ph}}_{2}{\mathrm{CH}}^{+}\\ \left(\mathrm{III}\right)\mathrm{Cyclotropylium}\mathrm{cation}\\ \left(\mathrm{IV}\right){\mathrm{CH}}_{3}{\mathrm{CH}}_{2}\overset{+}{\mathrm{C}}{\mathrm{H}}_{2}{\mathrm{CH}}_{3}\)

a

III > I > II > IV

b

I > II > III > IV

c

II > III > IV > I

d

IV > I > II > III

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Q80

PYQ

The sum of sigma \((\sigma )\) and pi \((\pi )\) bonds in Hex-1,3-dien-5-yne is_______

[JEE Main 2025, 29 Jan (Shift 1)]

a

12

b

13

c

14

d

15

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Q81

PYQ

The interaction between \(\pi\) bond and lone pair of electrons present on an adjacent atom is responsible for:

a

Electromeric effect

b

Hyperconjugation

c

Inductive effect

d

Resonance effect

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Q82

PYQ

The Lassaigne's extract is boiled with dil \(\mathrm{HNO}_3\) before testing for halogens because,

[JEE Main 2024, 30 Jan (Shift 1)]

a

\(\mathrm{Ag}_2 \mathrm{S}\) is soluble in \(\mathrm{HNO}_3\).

b

\(\mathrm{AgCN}\) is soluble in \(\mathrm{HNO}_3\).

c

Silver halides are soluble in \(\mathrm{HNO}_3\).

d

\(\mathrm{Na}_2 \mathrm{S}\) and \(\mathrm{NaCN}\) are decomposed by \(\mathrm{HNO}_3\).

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Q83

PYQ

The Lassaigne's extract is boiled with dil \(\mathrm{HNO}_3\) before testing for halogens because,

[JEE Main 2024, 30 Jan (Shift 1)]

a

\(\mathrm{Ag}_2 \mathrm{S}\) is soluble in \(\mathrm{HNO}_3\).

b

\(\mathrm{AgCN}\) is soluble in \(\mathrm{HNO}_3\).

c

Silver halides are soluble in \(\mathrm{HNO}_3\).

d

\(\mathrm{Na}_2 \mathrm{S}\) and \(\mathrm{NaCN}\) are decomposed by \(\mathrm{HNO}_3\).

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Q84

PYQ

The molecular formula of second homologue in the homologous series of mono carboxylic acids is ..............

a

\(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O}_{2}\)

b

\(\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{2}\)

c

\(\mathrm{C}_{2} \mathrm{H}_{2} \mathrm{O}_{2}\)

d

\(\mathrm{CH}_{2} \mathrm{O}\)

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Q85

PYQ

The incorrect statement regarding conformations of ethane is:

[JEE Main 2024, 27 Jan (Shift 2)]

a

Ethane has infinite number of conformations

b

The dihedral angle in staggered conformation is 60°

c

Eclipsed conformation is the most stable conformation.

d

The conformations of ethane are interconvertible to one-another.

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Q86

PYQ

The incorrect statement regarding conformations of ethane is:

[JEE Main 2024, 27 Jan (Shift 2)]

a

Ethane has infinite number of conformations

b

The dihedral angle in staggered conformation is 60°

c

Eclipsed conformation is the most stable conformation.

d

The conformations of ethane are interconvertible to one-another.

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Q87

PYQ

Methods used for purification of organic compounds are based on :

[JEE Main 2024, 09 Apr (Shift 1)]

a

nature of compound and presence of impurity.

b

presence of impurity only.

c

neither on nature of compound nor on the impurity present.

d

nature of compound only.

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Q88

PYQ

Methods used for purification of organic compounds are based on :

[JEE Main 2024, 09 Apr (Shift 1)]

a

nature of compound and presence of impurity.

b

presence of impurity only.

c

neither on nature of compound nor on the impurity present.

d

nature of compound only.

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Q89

PYQ

A liquid compound \((\mathrm{x})\) can be purified by steam distillation only if it is

[Re-NEET 2020]

a

Not steam volatile, miscible with water

b

Steam volatile, miscible with water

c

Not steam volatile, immiscible with water

d

Steam volatile, immiscible with water

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Q90

PYQ

In Carius method of estimation of halogen, \(\ 0.2 \mathrm{~g}\) of an organic compound gave \(\ 0.188 \mathrm{~g}\) of \(\mathrm{AgBr}\). The percentage of bromine in the compound is

a

40 %

b

32 %

c

56 %

d

28 %

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Q91

PYQ

Complete combustion of \(1.80 \mathrm{~g}\) of an oxygen containing compound \(\left(\mathrm{C}_{\mathrm{x}} \mathrm{H}_{\mathrm{y}} \mathrm{O}_{\mathrm{z}}\right)\) gave \(2.64 \mathrm{~g}\) of \(\mathrm{CO}_{2}\) and 1.08 g of \(\mathrm{H}_{2} \mathrm{O}\). The percentage of oxygen in the organic compound is

[JEE Main 2021, 25 Feb (Shift 1)]

a

53.33

b

50.33

c

63.53

d

51.63

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Q92

PYQ

A student has been given 0.314 g of an organic compound and asked to estimate Sulphur. During the experiment, the student has obtained 0.4813 g of barium sulphate. The percentage of sulphur present in the compound is …….. (Given Molar mass in g mol^–1 S : 32, BaSO₄ : 233)

a

63.15%

b

21.05%

c

48.24%

d

42.10%

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Q93

PYQ

A solution of \(FeCl _3\) when treated with \(K _4\left[ Fe ( CN )_6\right]\) gives a prussiun blue precipitate due to the formation of

[JEE Main 2023, 1 Feb (Shift 1)]

a

\(K \left[ Fe _2( CN )_6\right]\)

b

\(Fe \left[ Fe ( CN )_6\right]\)

c

\(Fe _3\left[ Fe ( CN )_6\right]_2\)

d

\(Fe _4\left[ Fe ( CN )_6\right]_3\)

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Q94

PYQ

Which one of the following methods can be used to obtain highly pure metal which is liquid at room temperature?

[NEET 2021]

a

Electrolysis

b

Chromatography

c

Distillation

d

Zone refining

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Q95

PYQ

The functional groups that are responsible for the ion- exchange property of cation and anion exchange resins, respectively, are:

[JEE Main 2021, 17 Mar (Shift 2)]

a

\(-{\mathrm{SO}}_{3}\mathrm{H}\) and \(-{\mathrm{NH}}_{2}\)

b

\(-{\mathrm{SO}}_{3}\mathrm{H}\) and -COOH

c

\(-{\mathrm{NH}}_{2}\) and -COOH

d

\(-{\mathrm{NH}}_{2}\) and \(-{\mathrm{SO}}_{3}\mathrm{H}\)

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Q96

PYQ

Which of the following compound is added to the sodium extract before addition of silver nitrate for testing of halogens?

[JEE Main 2021, 25 Feb (Shift 2)]

a

Sodium hydroxide

b

Hydrochloric acid

c

Nitric acid

d

Ammonia

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Q97

PYQ

The number of compound/s given below which contain/s -COOH group is

(a) Sulphanilic acid
(b) Picric acid
(c) Aspirin
(d) Ascorbic acid

[JEE Main 2021, 25 Feb (Shift 2)]

a

1

b

2

c

3

d

0

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Q98

PYQ

When \(0.01 \mathrm{~mol}\) of an organic compound containing \(60 \%\) carbon was burnt completely, \(4.4 \mathrm{~g}\) of \(\mathrm{CO}_{2}\) was produced. The molar mass of compound is \(\mathrm{g} \mathrm{mol}^{-1}\) (Nearest integer)

[JEE Main 2023, 29 Jan (Shift 2)]

a

200

b

100

c

50

d

40

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Q99

PYQ

Using column chromatography, mixture of two compounds ' \(A\) ' and ' \(B\) ' was separated. 'A' eluted first, this indicates ' \(B\) ' has

[JEE Main 2023, 10 Apr (Shift 1)]

a

Low \(R _{ f }\), weaker adsorption

b

High \(R _{ f }\), stronger adsorption

c

High \(R _{ f }\), weaker adsorption

d

Low \(R _{ f }\), stronger adsorption

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Q100

PYQ

Which purification technique is used for high boiling organic liquid compound (decomposes near its boiling point) ?

[JEE Main 2021, 22 Jul (Shift 2)]

a

Fractional distillation

b

Steam distillation

c

Simple distillation

d

Reduced pressure distillation

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Q101

PYQ

Compound that will give positive Lassaigne's test for both nitrogen and halogen is

[JEE Main 2023, 29 Jan (Shift 1)]

a

\(N _2 H _4 \cdot HCl\)

b

\(CH _3 NH _2 \cdot HCl\)

c

\(NH _4 Cl\)

d

\(NH _2 OH \cdot HCl\)

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Q102

PYQ

Which one of the following set of elements can be detected using sodium fusion extract?

[JEE Main 2021, 27 Jul (Shift 2)]

a

Halogens, Nitrogen, Oxygen, Sulfur

b

Sulfur, Nitrogen, Phosphorous, Halogens

c

Phosphorous, Oxygen, Nitrogen, Halogens

d

Nitrogen, Phosphorous, Carbon, Sulfur

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Q103

PYQ

\(\mathrm{0.400 ~g}\) of an organic compound \(\mathrm{( X )}\) gave \(\mathrm{0.376 ~g}\) of \(\mathrm{AgBr}\) in Carius method for estimation of bromine. \(\%\) of bromine in the compound \(( X )\) is _________.
(Given: Molar mass \(\mathrm{AgBr =188 ~g mol ^{-1} Br =80 ~g mol ^{-1}}\) )

[JEE Main 2023, 13 Apr (Shift 2)]

a

50

b

60

c

70

d

40

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Q104

PYQ

In the sulphur estimation, \(\mathrm{0.471 ~g}\) of an organic compound gave \(\mathrm{1.44 ~g}\) of barium sulphate. The percentage of sulphur in the compound is _____ \(\%\). (Nearest integer)
(Atomic mass of \(Ba =137 u\) ).

[JEE Main 2021, 26 Aug (Shift 2)]

a

22

b

32

c

42

d

52

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Q105

PYQ

In sulphur estimation, 0.471 g of an organic compound gave \(\mathrm{1.4439 ~g}\) of barium sulphate.
The percentage of sulphur in the compound is ______________(Nearest Integer)
(Given: Atomic mass Ba: \(137 u : S : 32 u , O : 16 u\) )

a

42

b

52

c

62

d

72

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Q106

PYQ

On complete combustion, \(0.492 \mathrm{~g}\) of an organic compound gave \(0.792 \mathrm{~g}\) of \(\mathrm{CO}_{2}\). The % of carbon in the organic compound is _____ (Nearest integer)

[JEE Main 2023, 31 Jan (Shift 1)]

a

54

b

64

c

74

d

44

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Q107

PYQ

\(0.8 \mathrm{~g}\) of an organic compound was analysed by Kjeldahl's method for the estimation of nitrogen. If the percentage of nitrogen in the compound was found to be \(42 \%\), then _____ \(ml\) of \(1 ~\mathrm{M} \mathrm{~H _2 SO _4}\) would have been neutralized by the ammonia evolved during the analysis

[JEE Main 2021, 25 Jul (Shift 2)]

a

12

b

14

c

16

d

18

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Q108

PYQ

The transformation occurring in Dumas method is given below:

\({\mathrm{C}}_{2}{\mathrm{H}}_{7}\mathrm{N}+\left(2x+\frac{y}{2}\right)\mathrm{CuO}\to x{\mathrm{CO}}_{2}+\frac{y}{2}{\mathrm{H}}_{2}\mathrm{O}+\frac{z}{2}{\mathrm{N}}_{2}+\left(2x+\frac{y}{2}\right)\mathrm{Cu}\)

The value of \( y \) is ___ (Integer answer)

[JEE Main 2021, 31 Aug (Shift 2)]

a

7

b

14

c

21

d

28

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Q109

PYQ

When \(0.15 ~g\) of an organic compound was analyzed using carius method for estimation of bromine, \(0.2397 ~g\) of \(\mathrm{AgBr}\) was obtained. The percentage of bromine in the organic compound is _____ (Nearest Integer) (Atomic mass: \(Ag =108, Br =80)\)

[JEE Main 2021, 20 Jul (Shift 2)]

a

68

b

78

c

88

d

98

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Q110

PYQ

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): A simple distillation can be used to separate a mixture of propanol and propanone.
Reason (R): Two liquids with a difference of more than \(20^{\circ} \mathrm{C}\) in their boiling points can be separated by simple distillations.
In the light of the above statements, choose the most appropriate answer from the options given below:

[JEE Main 2021, 31 Aug (Shift 1)]

a

(A) is false but (R) is true.

b

Both (A) and (R) are correct but is(R) not the correct explanation of (A).

c

(A) is true but (R) is false.

d

Both (A) and (R) are correct and (R) is the correct explanation of (A).

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Q111

PYQ

Given below are two statements

Statement-I: Tropolone is an aromatic compound and has \(8 \pi\) electrons.
Statement-II: \(\pi\) electrons of \(> C =O\) group in tropolone is involved in aromaticity.

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

a

Both Statement-I and Statement-II are true

b

Statement-I is true but Statement-II is false

c

Statement-I is false but Statement-II is true

d

Both Statement-I and Statement-II are false

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Q112

PYQ

Complete combustion of \(750 \mathrm{~g}\) of an organic compound provides \(420 \mathrm{~g}\) of \(\mathrm{CO}_{2}\) and \(210 \mathrm{~g}\) of \(\mathrm{H}_{2} \mathrm{O}\). The percentage composition of carbon and hydrogen in organic compound is 15.3 and respectively. (Round off to the nearest Integer).

[JEE Main 2021, 16 Mar (Shift 1)]

a

3

b

6

c

9

d

12

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Q113

PYQ

The potassium ferrocyanide solution gives a Prussian blue colour, when added to:

[JEE Main 2021, 1 Sep (Shift 2)]

a

\(CoCl _3\)

b

\(FeCl _3\)

c

\(FeCl _2\)

d

\(CoCl _2\)

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Q114

PYQ

Compound that will give positive Lassaigne's test for both nitrogen and halogen is

a

\(N _2 H _4 \cdot HCl\)

b

\(CH _3 NH _2 \cdot HCl\)

c

\(NH _4 Cl\)

d

\(NH _2 OH \cdot HCl\)

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