Is Purification and Characterisation of Organic Compounds an important chapter for JEE?

Judged by how often it is actually tested, it appears in roughly 62% of papers. Chapters above about 50% are effectively guaranteed to show up every session, so they repay thorough preparation; lower-frequency chapters are better treated as targeted revision.

Purification and Characterisation of Organic Compounds JEE Previous Year Questions with Answers

Q1·ChemistryNumericalJEE Advanced 2026

Passage: Consider the following reaction sequence in which J, K, L and M are the major products. Given: Atomic mass (in amu): H : 1, C : 12, N : 14, O : 16, S : 32, Br : 80, Ba : 137 Question: The volume of 1 M aqueous

H_{2}SO_{4}

required to completely neutralize the ammonia evolved from 5.72 g of L in Kjeldahl's method of nitrogen estimation is ____ mL.

Q2·ChemistryNumericalJEE Advanced 2026

Passage: Consider the following reaction sequence in which J, K, L and M are the major products. Given: Atomic mass (in amu): H : 1, C : 12, N : 14, O : 16, S : 32, Br : 80, Ba : 137 Question: In sulphur estimation by Carius method, the amount of

BaSO_{4}

formed from 3.79 g of M is ____ g.

Q3·ChemistrySingle correctJEE Main 2026

Given below are two statements: Statement I: Vapours of the liquid with higher boiling point condense before vapours of the liquid with lower boiling points in fractional distillation. Statement II: The vapours rising up in the fractionating column become richer in high boiling component of the mixture. 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)Both Statement I and Statement II are false
(C)Statement I is true but Statement II is false
(D)Statement I is false but Statement II is true

Q4·ChemistrySingle correctJEE Main 2026

R_f

value for 2-methylpropene in a solvent system (Ethyl acetate + ether) is 0.42. 2-methylpropene is treated with dilute H₂SO₄ to give major organic product (X).

R_f

value for (X) in the same solvent system under identical condition will be:

(A)0.42
(B)0.82
(C)0.62
(D)0.12

Q5·ChemistrySingle correctJEE Main 2026

Given below are two statements : Statement I : A mixture of

\mathrm{C_{12}H_{22}O_{11}}

(sugar) and NaCl can be separated by dissolving sugar in alcohol, due to differential solubility. Statement II : Rose essence from rose petals is seperated by steam distillation due to its high volatility and insolubility in

\mathrm{H_{2}O}

. 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)Both Statement I and Statement II are false
(C)Statement I is true but Statement II is false
(D)Statement I is false but Statement II is true

Q6·ChemistryNumericalJEE Main 2026

In an estimation of sulphur by Carius method 0.2 g of the substance gave 0.6 g of BaSO

_4

. The percentage of sulphur in the substance is _____ %. (Given molar mass in g mol

^{-1}

S : 32, BaSO

_4

: 233)

Q7·ChemistrySingle correctJEE Main 2026

Match List-I (Purification technique) with List-II (Used to separate). Choose the correct answer from the options given below :

List-I (Purification technique)	List-II (Used to separate)
A.Simple distillation	I.Steam volatile compound
B.Fractional distillation	II.Two liquids with large difference in boiling points
C.Steam distillation	III.Liquid decomposing at its boiling point
D.Distillation under reduced pressure	IV.Two liquids with close boiling points

(A)A-II, B-III, C-I, D-IV
(B)A-II, B-IV, C-I, D-III
(C)A-II, B-IV, C-III, D-I
(D)A-IV, B-III, C-II, D-I

Q8·ChemistryNumericalJEE Main 2026

2.0 g of a bromo hydrocarbon

(X)

was subjected to Carius analysis, gave 3.36 g of

AgBr

. The percentage of carbon in the compound

(X)

is 26.7%. Total number of carbon atoms in the empirical formula for compound

(X)

is _______. (Given molar mass in g

mol^{-1}

H:1, C:12, Br:80, Ag:108)

Q9·ChemistrySingle correctJEE Main 2026

Match the LIST-I (Compound) with LIST-II (Test). Choose the correct answer from the options given below:

List-I (Compound)	List-II (Test)
A.Cyclohexanol	I.Hinsberg's reagent test
B.Cyclohexylamine	II.Phthalein dye test
C.Cyclohexanecarbaldehyde	III.Lucas test
D.Phenol	IV.Tollen's test

(A)A-III, B-I, C-IV, D-II
(B)A-III, B-IV, C-I, D-II
(C)A-I, B-III, C-II, D-IV
(D)A-I, B-II, C-III, D-IV

Q10·ChemistryNumericalJEE Main 2026

In sulphur estimation, 2.0 × 10

^{-3}

mol of an organic compound (X) (molar mass 76 g mol

^{-1}

) gave 0.4813 g of barium sulphate (molar mass 233 g mol

^{-1}

). The percentage of sulphur in the compound (X) is ______ ×10

^{-1}

% (Nearest integer)

Q11·ChemistrySingle correctJEE Main 2026

Complete combustion of

X

g of an organic compound gave 0.25 g of

CO_2

and 0.12 g of

H_2O

. If the % of carbon is 25% and of hydrogen is 4.89%, then

X =

_____

\times 10^{-3}

g. (Nearest integer) (Molar mass of C, H and O are

12, 1

and 16 g mol

^{-1}

respectively.)

(A)273
(B)27
(C)2730
(D)227

Q12·ChemistrySingle correctJEE Main 2026

Given below are two statements : Statement (I) : 1,2,3-Trihydroxypropane can be separated from water by simple distillation. Statement (II) : An azeotropic mixture cannot be separated by fractional distillation. 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)Both Statement I and Statement II are false
(C)Statement I is true but Statement II is false
(D)Statement I is false but Statement II is true

Q13·ChemistrySingle correctJEE Main 2026

Match List - I (Mixture of Compounds) with List - II (Reagent used to distinguish). Choose the correct answer from the options given below :

List - I (Mixture of Compounds)	List - II (Reagent used to distinguish)
A.Diethyl amine + Ethyl amine	I.Bromine water
B.Acetaldehyde + Acetone	II. $\mathrm{CHCl_{3}} + \mathrm{KOH}$ , $\Delta$
C.Ethanol + Phenol	III.Neutral $\mathrm{FeCl_{3}}$
D.Benzoic acid + Cinnamic acid	IV.Ammonical silver nitrate

(A)A-IV, B-II, C-I, D-III
(B)A-IV, B-II, C-III, D-I
(C)A-II, B-IV, C-I, D-III
(D)A-II, B-IV, C-III, D-I

Q14·ChemistryNumericalJEE Main 2026

Consider the following reactions sequence When the product (P) is subjected to Carius analysis using

AgNO_3

, 1.0 g of the product (P) will produce ________ g of the precipitate of AgBr. (Nearest Integer) (Given: molar mass in g mol

^{-1}

C : 12, H : 1, O : 16, N : 14, Br : 80, Ag : 108)

Q15·ChemistrySingle correctJEE Main 2026

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,

BaSO_4

: 233)

(A)42.10%
(B)63.15%
(C)21.05%
(D)48.24%

Q16·ChemistrySingle correctJEE Main 2026

Method used for separation of mixture of products (B and C) obtained in the following reaction is:

(A)Simple distillation
(B)sublimation
(C)steam distillation
(D)fractional distillation

Q17·ChemistryNumericalJEE Main 2026

0.53 g of an organic compound (x) when heated with excess of nitric acid (concentrated) and then with silver nitrate gave 0.75 g of silver bromide precipitate. 1.0 g of (x) gave 1.32 g of CO

_{2}

gas on combustion. The percentage of hydrogen in the compound (x) is ________ %. [Nearest Integer] [Given : Molar mass in g mol

^{-1}

H : 1, C : 12, Br : 80, Ag : 108, O : 16; Compound (x) : C

_{x}

H

_{y}

Br

_{z}

]

Q18·ChemistryNumericalJEE Main 2026

0.25 g of an organic compound "A" containing carbon, hydrogen and oxygen was analysed using the combustion method. There was an increase in mass of

\text{CaCl}_{2}

tube and potash tube at the end of the experiment. The amount was found to be 0.15 g and 0.1837 g, respectively. The percentage of oxygen in compound A is _______ %. (Nearest integer) (Given : molar mass in

\text{g mol}^{-1}

H : 1, C : 12, O : 16)

Q19·ChemistryNumericalJEE Main 2026

In Dumas method for estimation of nitrogen, 0.50 g of an organic compound gave 70 mL of nitrogen collected at 300 K and 715 mm pressure. The percentage of nitrogen in the organic compound is ______% (Aqueous tension at 300 K is 15 mm).

Q20·ChemistrySingle correctJEE Main 2026

In Carius method 0.2425 g of an organic compounds gave 0.5253 g silver chloride. The percentage of chlorine in the organic compound is

(A)53.58%
(B)87.65%
(C)37.57%
(D)34.79%

Q21·ChemistrySingle correctJEE Main 2026

Given below are two statements : Statement-I : Sublimation is used for the separation and purification of compounds with low melting point. Statement-II : The boiling point of a liquid increases as the external pressure is reduced. 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)Statement-I is true but Statement-II is false.
(C)Both Statement-I and Statement-II are true.
(D)Both Statement-I and Statement-II are false.

Q22·ChemistryNumericalJEE Main 2026

Sodium fusion extract of an organic compound (Y) with CHCl

_3

and chlorine water gives violet color to the CHCl

_3

layer. 0.15g of (Y) gave 0.12 g of the silver halide precipitate in Carius method. Percentage of halogen in the compound (Y) is __________ . (Nearest integer). (Given : molar mass g mol

^{-1}

C : 12, H : 1, Cl : 35.5, Br : 80, I : 127)

Q23·ChemistrySingle correctJEE Main 2026

When 1 g of compound (X) is subjected to Kjeldahl's method for estimation of nitrogen, 15 mL, 1M

H_2SO_4

was neutralized by ammonia evolved. The percentage of nitrogen in compound (X) is :

(A)21
(B)0.42
(C)42
(D)0.21

Q24·ChemistrySingle correctJEE Main 2026

By usual analysis, 1.00g of compound (X) gave 1.79g of magnesium pyrophosphate. The percentage of phosphorus in compound (X) is: (nearest integer) (Given, molar mass in

\text{g mol}^{-1}

: O = 16, Mg = 24, P = 31)

(A)50
(B)30
(C)20
(D)40

Q25·ChemistrySingle correctJEE Main 2026

In Carius method, 0.75 g of an organic compound gave 1.2 g of barium sulphate, find percentage of sulphur (molar mass 32 g

mol^{-1}

). Molar mass of barium sulphate is 233 g

mol^{-1}

.

(A)4.55%
(B)10.30%
(C)21.97%
(D)16.48%

Q26·ChemistryNumericalJEE Advanced 2025

The monomer (X) involved in the synthesis of Nylon 6,6 gives positive carbylamine test. If 10 moles of X are analyzed using Dumas method, the amount (in grams) of nitrogen gas evolved is ______. Use: Atomic mass of N (in amu) = 14

Q27·ChemistrySingle correctJEE Main 2025

Match the LIST-I (Reagent) with LIST-II (Functional Group detected). Choose the correct answer from the options given below:

LIST-I (Reagent)	LIST-II (Functional Group detected)
A.Sodium bicarbonate solution	I.double bond/unsaturation
B.Neutral ferric chloride	II.carboxylic acid
C.ceric ammonium nitrate	III.phenolic - OH
D.alkaline $KMnO_4$	IV.alcoholic - OH

(A)A-II, B-III, C-IV, D-I
(B)A-II, B-III, C-I, D-IV
(C)A-III, B-II, C-IV, D-I
(D)A-II, B-IV, C-III, D-I

Q28·ChemistrySingle correctJEE Main 2025

On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 g

H_2O

and 0.307 g

CO_2

. The percentages of hydrogen and oxygen in the given organic compound respectively are:

(A) $53.41,\ 39.6$
(B) $6.72,\ 53.41$
(C) $7.55,\ 43.85$
(D) $6.72,\ 39.87$

Q29·ChemistrySingle correctJEE Main 2025

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:

(A)benzoic acid
(B)benzoic acid and aniline
(C)benzoic acid and chlorobenzene
(D)chlorobenzene and aniline

Q30·ChemistryIntegerJEE Main 2025

In Dumas' method, 292 mg of an organic compound released 50 mL of nitrogen gas (

N_2

) 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 K = 15 mm Hg)

Q31·ChemistryIntegerJEE Main 2025

An organic compound weighing 500 mg, produced 220 mg of CO

_2

on complete combustion. The percentage composition of carbon in the compound is ______ % (nearest integer). (Given molar mass in g mol

^{-1}

of C: 12, O: 16)

Q32·ChemistryIntegerJEE Main 2025

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

Q33·ChemistrySingle correctJEE Main 2025

Match List-I (Separation of) with List-II (Separation Technique). Choose the correct answer from the options given below:

List-I (Separation of)	List-II (Separation Technique)
A.Aniline from aniline-water mixture	I.Simple distillation
B.Glycerol from spent-lye in soap industry	II.Fractional distillation
C.Different fractions of crude oil in petroleum industry	III.Distillation at reduced pressure
D.Chloroform-Aniline mixture	IV.Steam distillation

(A)(A)-(IV), (B)-(III), (C)-(II), (D)-(I)
(B)(A)-(I), (B)-(III), (C)-(II), (D)-(IV)
(C)(A)-(III), (B)-(IV), (C)-(I), (D)-(II)
(D)(A)-(I), (B)-(III), (C)-(IV), (D)-(II)

Q34·ChemistrySingle correctJEE Main 2025

In Dumas' method for estimation of nitrogen, 0.4 g 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 is: (Given: Aqueous tension at 300 K = 15 mm Hg)

(A)15.71%
(B)20.95%
(C)17.46%
(D)7.85%

Q35·ChemistryIntegerJEE Main 2025

0.5 g of an organic compound on combustion gave 1.46 g of

CO_2

and 0.9 g of

H_2O

. The percentage of carbon in the compound is __________. (Nearest integer) [Given molar mass in g mol

^{-1}

: C : 12, H : 1, O : 16]

Q36·ChemistryIntegerJEE Main 2025

During estimation of nitrogen by Dumas' method of compound X (0.42 g), shown in the figure, __________ mL of

N_2

gas will be liberated at STP. (nearest integer) (Given molar mass in g mol

^{-1}

: C : 12, H : 1, N : 14)

Q37·ChemistrySingle correctJEE Main 2025

Match List-I (Purification technique) with List-II (Mixture of organic compounds). Choose the correct answer from the options given below:

List-I (Purification technique)	List-II (Mixture of organic compounds)
A.Distillation (simple)	I.Diesel + Petrol
B.Fractional distillation	II.Aniline + Water
C.Distillation under reduced pressure	III.Chloroform + Aniline
D.Steam distillation	IV.Glycerol + Spent-lye

(A)(A)-(II), (B)-(III), (C)-(IV), (D)-(I)
(B)(A)-(II), (B)-(IV), (C)-(I), (D)-(III)
(C)(A)-(III), (B)-(IV), (C)-(II), (D)-(I)
(D)(A)-(III), (B)-(I), (C)-(IV), (D)-(II)

Q38·ChemistrySingle correctJEE Main 2025

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 is: (Aqueous tension at 300 K

=15

mm Hg)

(A)1.257
(B)20.87
(C)18.67
(D)12.57

Q39·ChemistryIntegerJEE Main 2025

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}

%. (Molar mass: O = 16, S = 32, Ba = 137 g mol⁻¹)

Q40·ChemistrySingle correctJEE Main 2025

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, paper acts as a stationary phase. In the light of the above statements, choose the correct answer from the options given below:

(A)Both Statement I and Statement II are false
(B)Statement I is true but Statement II is false
(C)Both Statement I and Statement II are true
(D)Statement I is false but Statement II is true

Q41·ChemistrySingle correctJEE Main 2025

The purification method based on the following physical transformation is: Solid

\xrightarrow{\text{Heat}}

Vapour

\xrightarrow{\text{Cool}}

Solid.

(A)Sublimation
(B)Distillation
(C)Crystallization
(D)Extraction

Q42·ChemistryIntegerJEE Main 2025

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 __________

\times10^{-1}

%. (Nearest integer) (Given : Molar mass of Ag = 108 and Br is 80 g mol

^{-1}

)

Q43·ChemistrySingle correctJEE Main 2025

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. H₂SO₄. 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 false but Statement II is true
(C)Both Statement I and Statement II are false
(D)Statement I is true but Statement II is false

Q44·ChemistryIntegerJEE Main 2025

During "S" estimation, 160 mg of an organic compound gives 466 mg of barium sulphate. The percentage of Sulphur in the given compound is _______ %. (Given molar mass in g mol

^{-1}

of Ba : 137, S : 32, O : 16)

Q45·ChemistrySingle correctJEE Main 2025

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 FeSO₄ and Na₄[Fe(CN)₆]. 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)Both Statement I and Statement II are false
(C)Statement I is false but Statement II is true
(D)Statement I is true but Statement II is false

Q46·ChemistrySingle correctJEE Main 2025

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)Both Statement I and Statement II are true
(B)Both Statement I and Statement II are false
(C)Statement I is true but Statement II is false
(D)Statement I is false but Statement II is true

Q47·ChemistryIntegerJEE Main 2025

In the Carius method for the estimation of halogens, 180 mg of an organic compound produced 143.5 mg of AgCl. The percentage composition of chlorine in the compound is ______ %. (molar masses: AgCl = 143.5, Ag = 108, Cl = 35.5)

Q48·ChemistryNumericalJEE Main 2024

In thin layer chromatography (TLC), the distance of spot A and B are 5 cm and 7 cm from the bottom of the TLC plate, respectively (as shown in the figure).

R_f

value of B is

x\times10^{-1}

times more than A. The value of x is _______.

Q49·ChemistrySingle correctJEE Main 2024

Methods used for purification of organic compounds are based on :

(A)neither on nature of compound nor on the impurity present.
(B)nature of compound only.
(C)nature of compound and presence of impurity.
(D)presence of impurity only.

Q50·ChemistrySingle correctJEE Main 2024

Match List-I (Test) with List-II (Observation). Choose the correct answer from the options given below:

List-I (Test)	List-II (Observation)
A. $Br_2$ water test	I.Yellow orange or orange red precipitate formed
B.Ceric ammonium nitrate test	II.Reddish orange colour disappears
C.Ferric chloride test	III.Red colour appears
D.2,4-DNP test	IV.Blue, Green, Violet or Red colour appear

(A)A-I, B-II, C-III, D-IV
(B)A-II, B-III, C-IV, D-I
(C)A-III, B-IV, C-I, D-II
(D)A-IV, B-III, C-II, D-I

Q51·ChemistrySingle correctJEE Main 2024

Given below are two statements: Statement (I): Kjeldahl method is applicable to estimate nitrogen in pyridine. Statement (II): The nitrogen present in pyridine can easily be converted into ammonium sulphate in Kjeldahl method. In the light of the above statements, choose the correct answer from the options given below.

(A)Both Statement I and Statement II is false
(B)Statement I is false but Statement II is true
(C)Both Statement I and Statement II is true
(D)Statement I is true but Statement II is false

Q52·ChemistrySingle correctJEE Main 2024

Which of the following statements are correct? A. Glycerol is purified by vacuum distillation because it decomposes at its normal boiling point. B. Aniline can be purified by steam distillation as aniline is miscible in water. C. Ethanol can be separated from ethanol-water mixture by azeotropic distillation because it forms azeotrope. D. An organic compound is pure, if mixed M.P. is remained same. Choose the most appropriate answer from the options given below:

(A)A, B, C only
(B)A, C, D only
(C)B, C, D only
(D)A, B, D only

Q53·ChemistrySingle correctJEE Main 2024

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

(A)Organic compounds run faster than solvent in the thin layer chromatographic plate.
(B)Non-polar compounds are retained at top and polar compounds come down in column chromatography.
(C) $R_f$ of a polar compound is smaller than that of a non-polar compound.
(D) $R_f$ is an integral value.

Q54·ChemistryNumericalJEE Main 2024

In a paper chromatography experiment, the solvent front rises to 12.5 cm. From the base line, sample A rises to 5.0 cm and sample C rises to 10.0 cm. The ratio of the

R_f

values of sample A and sample C is

x \times 10^{-2}

. The value of

x

is __________.

Q55·ChemistrySingle correctJEE Main 2024

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)B only
(B)C and D only
(C)A and B only
(D)A only

Q56·ChemistrySingle correctJEE Main 2024

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

(A)Phenyl hydrazine
(B)Glycine
(C)Urea
(D)Hydrazine

Q57·ChemistrySingle correctJEE Main 2024

In Kjeldahl's method for estimation of nitrogen,

CuSO_4

acts as:

(A)Reducing agent
(B)Catalytic agent
(C)Hydrolysis agent
(D)Oxidising agent

Q58·ChemistrySingle correctJEE Main 2024

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

(A)crystallisation
(B)distillation under reduced pressure
(C)distillation
(D)steam distillation

Q59·ChemistrySingle correctJEE Main 2024

'Adsorption' principle is used for which of the following purification method?

(A)Extraction
(B)Chromatography
(C)Distillation
(D)Sublimation

Q60·ChemistrySingle correctJEE Main 2024

Match List-I (separation technique) with List-II (application). Choose the correct answer from the options given below:

List-I (Technique)	List-II (Application)
A.Distillation	I.Separation of glycerol from spent-lye
B.Fractional distillation	II.Aniline - Water mixture
C.Steam distillation	III.Separation of crude oil fractions
D.Distillation under reduced pressure	IV.Chloroform-Aniline

(A)A-IV, B-I, C-II, D-III
(B)A-IV, B-III, C-II, D-I
(C)A-I, B-II, C-IV, D-III
(D)A-II, B-III, C-I, D-IV

Q61·ChemistrySingle correctJEE Main 2024

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

(A)Column Chromatography
(B)Sublimation
(C)Distillation
(D)Differential Extraction

Q62·ChemistrySingle correctJEE Main 2024

The Lassaigne’s extract is boiled with dil

HNO_3

before testing for halogens because:

(A) $AgCN$ is soluble in $HNO_3$
(B)Silver halides are soluble in $HNO_3$
(C) $Ag_2S$ is soluble in $HNO_3$
(D) $Na_2S$ and $NaCN$ are decomposed by $HNO_3$

Q63·ChemistryNumericalJEE Main 2024

On a thin layer chromatographic plate, an organic compound moved by

3.5\,cm

, while the solvent moved by

5\,cm

. The retardation factor of the organic compound is ___

\times10^{-1}

.

Q64·ChemistrySingle correctJEE Main 2024

Appearance of blood red colour, on treatment of the sodium fusion extract of an organic compound with

FeSO_4

in presence of concentrated

H_2SO_4

indicates the presence of element/s

(A)Br
(B)N
(C)N and S
(D)S

Q65·ChemistrySingle correctJEE Main 2024

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)B only
(B)A only
(C)A & B only
(D)C only

Q66·ChemistrySingle correctJEE Main 2024

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

(A)Fractional distillation
(B)Fractional distillation under reduced pressure
(C)Distillation
(D)Steam distillation

Q67·ChemistrySingle correctJEE Main 2023

Which the following statement is correct for paper chromatography?

(A)Water present in the mobile phase gets absorbed by the paper which then forms the stationary phase.
(B)Water present in the pores of the paper forms the stationary phase.
(C)Paper sheet forms the stationary phase.
(D)Paper and water present in its pores together form the stationary phase.

Q68·ChemistryNumericalJEE Main 2023

An organic compound gives

0.220\,g

of

CO_{2}

and

0.126\,g

of

H_{2}O

on complete combustion. If the

\%

of carbon is

24

then the

\%

of hydrogen is _____

\times 10^{-1}

. (Nearest integer)

Q69·ChemistryNumericalJEE Main 2023

0.400 g of an organic compound (X) gave 0.376 g of AgBr in Carius method for estimation of bromine. % of bromine in the compound (X) is ____. (Given: Molar mass AgBr = 188 g mol

^{-1}

, Br = 80 g mol

^{-1}

)

Q70·ChemistryNumericalJEE Main 2023

Three organic compounds A, B and C were allowed to run in thin layer chromatography using hexane and gave the result shown (see figure). The Rf value of the most polar compound is _________ × 10

^{-2}

Q71·ChemistrySingle correctJEE Main 2023

Thin layer chromatography of a mixture shows the observation given in the figure. The correct order of elution in the silica gel column chromatography is

(A)A, C, B
(B)B, C, A
(C)C, A, B
(D)B, A, C

Q72·ChemistrySingle correctJEE Main 2023

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

(A)lower R $_f$ , weaker adsorption
(B)high R $_f$ , stronger adsorption
(C)high R $_f$ , weaker adsorption
(D)low R $_f$ , stronger adsorption

Q73·ChemistrySingle correctJEE Main 2023

In a Carius tube, an organic compound 'X' is treated with sodium peroxide to form a mineral acid 'Y'. A solution of

\text{BaCl}_2

is added to 'Y' to form a precipitate 'Z'. 'Z' is used for the quantitative estimation of an extra element. 'X' could be:

(A)Cytosine
(B)Chloroxylenol
(C)A nucleotide
(D)Methionine

Q74·ChemistryNumericalJEE Main 2023

0.5 g of an organic compound (X) with 60% carbon will produce ____

\times 10^{-1}

g of

CO_2

on complete combustion.

Q75·ChemistrySingle correctJEE Main 2023

Match List I with List II. Choose the correct answer from the options given below:

List I (Element detected)	List II (Reagent used / Product formed)
A.Nitrogen	I. $Na_2[Fe(CN)_5NO]$
B.Sulphur	II. $AgNO_3$
C.Phosphorous	III. $Fe_4[Fe(CN)_6]_3$
D.Halogen	IV. $(NH_4)_2MoO_4$

(A)A-II, B-III, C-I, D-IV
(B)A-IV, B-II, C-I, D-III
(C)A-II, B-I, C-IV, D-III
(D)A-III, B-I, C-IV, D-II

Q76·ChemistrySingle correctJEE Main 2023

From the figure of column chromatography given below, identify incorrect statements. A. Compound 'c' is more polar than 'a' and 'b'. B. Compound 'a' spends least time on the column. C. Compound 'b' comes out of the column before 'c' and after 'a'. D. Compound 'a' spends more time in the column. Choose the correct answer from the options given below:

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

Q77·ChemistrySingle correctJEE Main 2023

Given below are two statements: Statement I: Sulphanilic acid gives esterification test for carboxyl group. Statement II: Sulphanilic acid gives red colour in Lassaigne's test for extra element detection. In the light of the above statements, choose most appropriate answer from the options given below:

(A)Statement I is incorrect but Statement II is correct
(B)Both Statement I and Statement II are incorrect
(C)Statement I is correct but Statement II is incorrect
(D)Both Statement I and Statement II are correct

Q78·ChemistrySingle correctJEE Main 2023

Match List I (qualitative test) with List II (class of compound it detects). Choose the correct answer from the options given below:

List I	List II
A.Molisch's Test	I.Peptide
B.Biuret Test	II.Carbohydrate
C.Carbylamine Test	III.Primary amine
D.Schiff's Test	IV.Aldehyde

(A)(A)-III, (B)-IV, (C)-I, (D)-II
(B)(A)-II, (B)-I, (C)-III, (D)-IV
(C)(A)-III, (B)-IV, (C)-II, (D)-I
(D)(A)-I, (B)-II, (C)-III, (D)-IV

Q79·ChemistryNumericalJEE Main 2023

On complete combustion,

0.492

g of an organic compound gave

0.792

g of

CO_2

. The % of carbon in the organic compound is ___ (Nearest integer)

Q80·ChemistrySingle correctJEE Main 2023

In Dumas method for the estimation of

N_2

, the sample is heated with copper oxide and the gas evolved is passed over:

(A)Copper oxide
(B)Ni
(C)Pd
(D)Copper gauze

Q81·ChemistrySingle correctJEE Main 2023

Match items of Column I (Mixture of compounds) with Column II (Separation Technique).

Column I (Mixture of compounds)	Column II (Separation Technique)
A. $H_2O$ / $CH_2Cl_2$	i.Crystallization
B.1-Tetralone / 4-Nitrophenol	ii.Differential solvent extraction
C.Kerosene / Naphthalene	iii.Column chromatography
D. $C_6H_{12}O_6$ / NaCl	iv.Fractional distillation

(A)A-(ii), B-(iii), C-(iv), D-(i)
(B)A-(i), B-(iii), C-(ii), D-(iv)
(C)A-(ii), B-(i), C-(iv), D-(iii)
(D)A-(iii), B-(ii), C-(i), D-(iv)

Q82·ChemistrySingle correctJEE Main 2023

Which of the following compounds would give the following set of qualitative analysis? (i) Fehling's Test: Positive (ii) Na fusion extract upon treatment with sodium nitroprusside gives a blood red colour but not prussian blue.

(A)(1)
(B)(2)
(C)(3)
(D)(4)

Q83·ChemistrySingle correctJEE Main 2023

Match List-I (Mixture) with List-II (Separation Technique). Choose the correct answer from the options given below:

List-I (Mixture)	List-II (Separation Technique)
A. $CHCl_3 + C_6H_5NH_2$	I.Steam distillation
B. $C_6H_{14} + C_5H_{12}$	II.Differential extraction
C. $C_6H_5NH_2 + H_2O$	III.Distillation
D.Organic compound in $H_2O$	IV.Fractional distillation

(A)A-IV, B-I, C-III, D-II
(B)A-III, B-IV, C-I, D-II
(C)A-III, B-I, C-IV, D-II
(D)A-II, B-I, C-III, D-IV

Q84·ChemistryNumericalJEE Main 2023

When

0.01

mol of an organic compound containing

60\%

carbon was burnt completely,

4.4\,g

of

CO_2

was produced. The molar mass of compound is _____

g\,mol^{-1}

(Nearest integer).

Q85·ChemistryNumericalJEE Main 2023

Following chromatogram was developed by adsorption of compound 'A' on a 6 cm TLC glass plate. Retardation factor of the compound 'A' is ________

\times 10^{-1}

.

Q86·ChemistrySingle correctJEE Main 2023

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

(A)NH $_2$ OH.HCl
(B)CH $_3$ NH $_2$ .HCl
(C)NH $_4$ Cl
(D)N $_2$ H $_4$ .HCl

Q87·ChemistryNumericalJEE Main 2023

In sulphur estimation, 0.471 g of an organic compound gave 1.4439 g of barium sulphate. The percentage of sulphur in the compound is _______ (nearest integer). (Given atomic mass Ba: 137u, S: 32u, O: 16u)

Q88·ChemistryNumericalJEE Advanced 2022

Consider the following reaction. On estimation of bromine in 1.00 g of

\mathbf{R}

using Carius method, the amount of AgBr formed (in g) is ________. [Given: Atomic mass of H = 1, C = 12, O = 16, P = 31, Br = 80, Ag = 108].

Q89·ChemistrySingle correctJEE Main 2022

Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R Assertion A : Thin layer chromatography is an adsorption chromatography. Reason : A thin layer of silica gel is spread over a glass plate of suitable size in thin layer chromatography which acts as an adsorbent. 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 A and R are true but R is NOT the correct explanation of A
(C)A is true but R is false
(D)A is false but R is true

Q90·ChemistryNumericalJEE Main 2022

On complete combustion of 0.492 g of an organic compound containing C, H and O, 0.7938 g of CO

_2

and 0.4428 g of H

_2

O was produced. The % composition of oxygen in the compound is _____.

Q91·ChemistryNumericalJEE Main 2022

A sample of 0.125 g of an organic compound when analysed by Duma's method yields 22.78 mL of nitrogen gas collected over KOH solution at 280K and 759 mm Hg. The percentage of nitrogen in the given organic compound is _____. (Nearest integer). (a) The vapour pressure of water at 280 K is 14.2 mm Hg (b) R = 0.082 L atm

\mathrm{K^{-1}\,mol^{-1}}

Q92·ChemistrySingle correctJEE Main 2022

In Carius method of estimation of halogen. 0.45 g of an organic compound gave 0.36 g of AgBr. Find out the percentage of bromine in the compound. (Molar masses : AgBr = 188 g

mol^{-1}

: Br = 80 g

mol^{-1}

)

(A)34.04%
(B)40.04%
(C)36.03%
(D)38.04%

Q93·ChemistrySingle correctJEE Main 2022

Match List-I with List-II List-I (Mixture) (A) Chloroform & Aniline (B) Benzoic acid & Napthalene (C) Water & Aniline (D) Napthalene & Sodium chloride List-II (Purification Process) (I) Steam distillation (II) Sublimation (III) Distillation (IV) Crystallisation

(A)(A)-(IV), (B)-(III), (C)-(I), (D)-(II)
(B)(A)-(III), (B)-(I), (C)-(IV), (D)-(II)
(C)(A)-(III), (B)-(IV), (C)-(II), (D)-(I)
(D)(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Q94·ChemistrySingle correctJEE Main 2022

Which technique among the following, is most appropriate in separation of a mixture of 100 mg of p-nitrophenol and picric acid ?

(A)Steam distillation
(B)2-5 ft long column of silica gel
(C)Sublimation
(D)Preparative TLC (Thin Layer Chromatography)

Q95·ChemistryNumericalJEE Main 2022

While estimating the nitrogen present in an organic compound by Kjeldahl's method, the ammonia evolved from 0.25 g of the compound neutralized 2.5 mL of 2 M

H_{2}SO_{4}

. The percentage of nitrogen present in organic compound is …… .

Q96·ChemistryNumericalJEE Main 2022

Kjeldahl's method was used for the estimation of nitrogen in an organic compound. The ammonia evolved from 0.55 g of the compound neutralised 12.5 mL of 1 M

H_2SO_4

solution. The percentage of nitrogen in the compound is _______ . (Nearest integer)

Q97·ChemistryNumericalJEE Main 2022

In the estimation of bromine, 0.5 g of an organic compound gave 0.40 g of silver bromide. The percentage of bromine in the given compound is __________% (nearest integer) (Relative atomic masses of Ag and Br are 108u and 80u, respectively).

Q98·ChemistrySingle correctJEE Main 2022

Which one of the following techniques is not used to spot components of a mixture separated on thin layer chromatographic plate?

(A) $I_2$ (Solid)
(B)U.V. Light
(C)Visualisation agent as a component of mobile phase
(D)Spraying of an appropriate reagent

Q99·ChemistrySingle correctJEE Main 2022

The formula of the purple colour formed in Laissaigne's test for sulphur using sodium nitroprusside is

(A) $NaFe[Fe(CN)_6]$
(B) $Na[Cr(NH_3)_2(NCS)_4]$
(C) $Na_2[Fe(CN)_5(NO)]$
(D) $Na_4[Fe(CN)_5(NOS)]$

Q100·ChemistryNumericalJEE Main 2022

The complete combustion of 0.492 g of an organic compound containing 'C', 'H' and 'O' gives 0.793g of CO

_2

and 0.442 g of H

_2

O. The percentage of oxygen composition in the organic compound is ______. (nearest integer)

Q101·ChemistryNumericalJEE Main 2022

0.25 g of an organic compound containing chlorine gave 0.40 g of silver chloride in Carius estimation. The percentage of chlorine present in the compound is _______. [in nearest integer] (Given: Molar mass of Ag is 108 g mol

^{-1}

and that of Cl is 35.5 g mol

^{-1}

)

Q102·ChemistrySingle correctJEE Main 2022

Which of the following is structure of a separating funnel?

(A)(A)
(B)(B)
(C)(C)
(D)(D)

Q103·ChemistryNumericalJEE Main 2022

On complete combustion 0.30 g of an organic compound gave 0.20 g of carbon dioxide and 0.10 g of water. The percentage of carbon in the given organic compound is ______ (Nearest Integer)

Q104·ChemistrySingle correctJEE Main 2022

Given below are two statements : Statement I : In 'Lassaigne's Test, when both nitrogen and sulphur are present in an organic compound, sodium thiocyanate is formed. Statement II : If both nitrogen and sulphur are present in an organic compound, then the excess of sodium used in sodium fusion will decompose the sodium thiocyanate formed to give NaCN and

Na_{2}S

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

(A)Both Statement I and Statement II are correct.
(B)Both Statement I and Statement II are incorrect.
(C)Statement I is correct but Statement II is incorrect.
(D)Statement I is incorrect but Statement II is correct.

Q105·ChemistrySingle correctJEE Main 2022

During halogen test, sodium fusion extract is boiled with concentrated HNO

_3

to

(A)remove unreacted sodium
(B)decompose cyanide or sulphide of sodium
(C)extract halogen from organic compound
(D)maintain the pH of extract

Q106·ChemistrySingle correctJEE Main 2022

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: A mixture contains benzoic acid and napthalene. The pure benzoic acid can be separated out by the use of benzene. Reason R: Benzoic acid is soluble in hot water. In the light of the above statements, choose the most appropriate answer from the options given below.

(A)Both A and R are true and R is the correct explanation of A.
(B)Both A and R are true but R is NOT the correct explanation of A.
(C)A is true but R is false.
(D)A is false but R is true.

Q107·ChemistrySingle correctJEE Main 2022

Phenol on reaction with dilute nitric acid, gives two products. Which method will be most effective for large scale separation ?

(A)Chromatographic separation
(B)Fractional Crystallisation
(C)Steam distillation
(D)Sublimation

Q108·ChemistryNumericalJEE Main 2022

0.2 g of an organic compound was subjected to estimation of nitrogen by Dumas method in which volume of N

_2

evolved (at STP) was found to be 22.400 mL. The percentage of nitrogen in the compound is____.[nearest integer] (Given: Molar mass of N

_2

is 28 mol

^{-1}

. Molar volume of N

_2

at STP : 22.4 L)

Q109·ChemistrySingle correctJEE Main 2021

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 :

(A)(A) is false but (R) is true.
(B)Both (A) and (R) are correct but (R) is 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)

Q110·ChemistryNumericalJEE Main 2021

The transformation occurring in Duma's method is given below :

\mathrm{C_2H_7N} + \left(2\mathrm{x} + \frac{y}{2}\right)\mathrm{CuO} \rightarrow \mathrm{xCO_2} + \frac{y}{2}\mathrm{H_2O} + \frac{z}{2}\mathrm{N_2} + \left(2\mathrm{x} + \frac{y}{2}\right)\mathrm{Cu}

The value of

y

is ________. (Integer answer)

Q111·ChemistryNumericalJEE Main 2021

The number of moles of CuO, that will be utilized in Dumas method for estimation nitrogen in a sample of 57.5g of N, N-dimethylaminopentane is ________

\times 10^{-2}

. (Nearest integer)

Q112·ChemistryNumericalJEE Main 2021

In Carius method for estimation of halogens, 0.2 g of an organic compound gave 0.188 g of AgBr. The percentage of bromine in the compound is ________ . (Nearest integer) [Atomic mass : Ag = 108, Br = 80]

Q113·ChemistryNumericalJEE Main 2021

In the sulphur estimation, 0.471 g of an organic compound gave 1.44 g of barium sulphate. The percentage of sulphur in the compound is ______%. (Nearest integer) (Atomic Mass of Ba = 137 u)

Q114·ChemistrySingle correctJEE Main 2021

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

(A)Halogens, Nitrogen, Oxygen, Sulfur
(B)Sulfur, Nitrogen, Phosphorous Halogens
(C)Phosphorous, Oxygen, Nitrogen, Halogens
(D)Nitrogen, Phosphorous, Carbon, Sulfur

Q115·ChemistryNumericalJEE Main 2021

An organic compound is subjected to chlorination to get compound A using 5.0 g of chlorine. When 0.5 g of compound A is reacted with

AgNO_3

[Carius Method], the percentage of chlorine in compound A is ____________ when it forms 0.3849 g of AgCl (Round off to the Nearest integer) (Atomic masses of Ag and Cl are 107.87 and 35.5 respectively)

Q116·ChemistryNumericalJEE Main 2021

0.8 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 M H

_2

SO

_4

would have been neutralized by the ammonia evolved during the analysis.

Q117·ChemistrySingle correctJEE Main 2021

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

(A)Fractional distillation
(B)Steam distillation
(C)Simple distillation
(D)Reduced pressure distillation

Q118·ChemistryNumericalJEE Main 2021

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

Q119·ChemistrySingle correctJEE Main 2021

In Carius method, halogen containing organic compound is heated with fuming nitric acid in the presence of :

(A) $\mathrm{AgNO_3}$
(B) $\mathrm{HNO_3}$
(C) $\mathrm{BaSO_4}$
(D) $\mathrm{CuSO_4}$

Q120·ChemistrySingle correctJEE Main 2021

Nitrogen can be estimated by Kjeldahl's method for which of the following compound ?

(A)(1)
(B)(2)
(C)(3)
(D)(4)

Q121·ChemistrySingle correctJEE Main 2021

Given below are two statements : Statement-I : Retardation factor (

\mathrm{R_f}

) can be measured in meter/centimeter. Statement-II :

\mathrm{R_f}

value of a compound remains constant in all solvents. Choose the most appropriate answer from the options given below:

(A)Statement-I is true but statement-II is false
(B)Both statement-I and statement-II are true
(C)Both statement-I and statement-II are false
(D)Statement-I is false but statement-II is true

Q122·ChemistrySingle correctJEE Main 2021

Match List-I with List-II. The correct match is :

List-I (Test/Reagents/Observation(s))	List-II (Species detected)
a.Lassaigne's Test	i.Carbon
b.Cu(II) oxide	ii.Sulphur
c.Silver nitrate	iii.N, S, P, and halogen
d.The sodium fusion extract gives black precipitate with acetic acid and lead acetate	iv.Halogen Specifically

(A)(a)-(iii), (b)-(i), (c)-(ii), (d)-(iv)
(B)(a)-(i), (b)-(iv), (c)-(iii), (d)-(ii)
(C)(a)-(iii), (b)-(i), (c)-(iv), (d)-(ii)
(D)(a)-(i), (b)-(ii), (c)-(iv), (d)-(iii)

Q123·ChemistrySingle correctJEE Main 2021

In chromotography technique, the purification of compound is independent of :

(A)Mobility or flow of solvent system
(B)Solubility of the compound
(C)Length of the column or TLC Plate
(D)Physical state of the pure compound

Q124·ChemistryNumericalJEE Main 2021

In Duma's method of estimation of nitrogen, 0.1840 g of an organic compound gave 30 mL of nitrogen collected at 287 K and 758 mm of Hg pressure. The percentage composition of nitrogen in the compound is ______. (Round off to the Nearest Integer). [Given : Aqueous tension at 287 K = 14 mm of Hg]

Q125·ChemistryNumericalJEE Main 2021

Complete combustion of 750 g of an organic compound provides 420 g of CO

_{2}

and 210 g of H

_{2}

O. The percentage composition of carbon and hydrogen in organic compound is 15.3 and ________ respectively. (Round off to the Nearest Integer)

Q126·ChemistrySingle correctJEE Main 2021

Which of the following is 'a' FALSE statement ?

(A)Carius tube used in the estimation of sulphur in an organic compound
(B)Kjedahl's method is used for the estimation of nitrogen in an organic compound
(C)Phosphoric acid produced on oxidation of phosphorus present in an organic compound is precipitated as Mg $_2$ P $_2$ O $_7$ by adding magnesia mixture
(D)Carius method is used for the estimation of nitrogen in an organic compound

Q127·ChemistrySingle correctJEE Main 2021

Given below are two statements : Statement I : A mixture of chloroform and aniline can be separated by simple distillation Statement II : When separating aniline from a mixture of aniline and water by steam distillation aniline boils below its boiling point In the light of the above statements, choose the most appropriate answer from the options given below

(A)Statement I is true, statement II is false
(B)Both Statement I and Statement II are true
(C)Both Statement I and Statement II are false
(D)Statement I is false, Statement II is true

Q128·ChemistrySingle correctJEE Main 2021

Ceric ammonium nitrate and CHCl

_3

/alc. KOH are used for the identification of functional groups present in __________and_________respectively.

(A)alcohol, amine
(B)amine, alcohol
(C)alcohol, phenol
(D)amine, phenol

Q129·ChemistryNumericalJEE Main 2021

Using the provided information in the following paper chromatogram: Fig: Paper chromatography for compounds A and B the calculated R

_{f}

value of A _______ × 10

^{-1}

.

Q130·ChemistrySingle correctJEE Main 2021

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

(A)Nitric acid
(B)Sodium hydroxide
(C)Hydrochloric acid
(D)Ammonia

Q131·ChemistrySingle correctJEE Main 2021

Complete combustion of 1.80 g of an oxygen containing compound (C

_{x}

H

_{y}

O

_{z}

) gave 2.64 g of CO

_{2}

and 1.08 g of H

_{2}

O. The percentage of oxygen in the organic compound is:

(A)63.53
(B)53.33
(C)51.63
(D)50.33

Q132·ChemistryNumericalJEE Main 2020

In an estimation of bromine by Carius method, 1.6 g of an organic compound gave 1.88 g of AgBr. The mass percentage of bromine in the compound is ______________ (Atomic mass, Ag = 108, Br = 80 g mol

^{-1}

)

Q133·ChemistrySingle correctJEE Main 2020

Match the following:

Test / Method	Reagent
i.Lucas Test	a.C $_6$ H $_5$ SO $_2$ Cl / aq. KOH
ii.Dumas method	b.HNO $_3$ / AgNO $_3$
iii.Kjeldahl's method	c.CuO / CO $_2$
iv.Hinsberg Test	d.Conc. HCl and ZnCl $_2$
	e.H $_2$ SO $_4$

(A)(i)-(d), (ii)-(c), (iii)-(b), (iv)-(e)
(B)(i)-(b), (ii)-(d), (iii)-(e), (iv)-(a)
(C)(i)-(d), (ii)-(c), (iii)-(e), (iv)-(a)
(D)(i)-(b), (ii)-(a), (iii)-(c), (iv)-(d)

Q134·ChemistrySingle correctJEE Main 2020

The Khjeldahl method of Nitrogen estimation fails for which of the following reaction products?

(A)(c) and (d)
(B)(b) and (c)
(C)(a) and (d)
(D)(a), (c) and (d)

Q135·ChemistrySingle correctJEE Main 2020

Glycerol is separated in soap industries by:

(A)Differential extraction
(B)Fractional distillation
(C)Distillation under reduced pressure
(D)Steam distillation

Q136·ChemistrySingle correctJEE Main 2020

A flask contains a mixture of isohexane and 3-methylpentane. One of the liquids boils at 63 °C while the other boils at 60 °C. What is the best way to separate the two liquids and which one will be distilled out first?

(A)fractional distillation, 3-methylpentane
(B)simple distillation, isohexane
(C)simple distillation, 3-methylpentane
(D)fractional distillation, isohexane

Q137·ChemistrySingle correctJEE Main 2020

Kjeldahl's method cannot be used to estimate nitrogen for which of the following compounds?

(A)NH $_2$ -C(=O)-NH $_2$
(B)C $_6$ H $_5$ NH $_2$
(C)C $_6$ H $_5$ NO $_2$
(D)CH $_3$ CH $_2$ -C $\equiv$ N

Q138·ChemistrySingle correctJEE Main 2020

A Chromatography column, packed with silica gel as stationary phase, was used to separate a mixture of compounds consisting of (a) benzanilide, (b) aniline and (c) acetophenone. When the column is eluted with a mixture of solvents, hexane; ethyl acetate(20:80), the sequence of obtained compounds is

(A)(b), (c) and (a)
(B)(a), (b) and (c)
(C)(c), (a) and (b)
(D)(b), (a) and (c)

Q139·ChemistrySingle correctJEE Main 2020

A solution of m-chloroaniline, m-chlorophenol and m-chlorobenzoic acid in ethyl acetate was extracted initially with a saturated solution of NaHCO

_3

to give fraction A. The left over organic phase was extracted with dilute NaOH solution to give fraction B. The final organic layer was labelled as fraction C. Fraction A, B and C contain respectively

(A)m-chlorobenzoic acid, m-chlorophenol and m-chloroaniline
(B)m-chlorophenol, m-chlorobenzoic acid and m-chloroaniline
(C)m-chlorobenzoic acid, m-chloroaniline and m-chlorophenol
(D)m-chloroaniline, m-chlorobenzoic acid and m-chlorophenol

Q140·ChemistrySingle correctJEE Main 2019

An organic compound 'A' is oxidized with Na

_2

O

_2

followed by boiling with HNO

_3

. The resultant solution is then treated with ammonium molybdate to yield a yellow precipitate. Based on above observation, the element present in the given compound is :

(A)Phosphorus
(B)Sulphur
(C)Nitrogen
(D)Fluorine

Q141·ChemistrySingle correctJEE Main 2019

In chromatography, which of the following statements is INCORRECT for R

_f

?

(A)R $_f$ value depends on the type of chromatography.
(B)The value of R $_f$ can not be more than one.
(C)Higher R $_f$ value means higher adsorption.
(D)R $_f$ value is dependent on the mobile phase.

Q142·ChemistrySingle correctJEE Main 2019

The principle of column chromatography is

(A)Differential absorption of the substances on the solid phase.
(B)Differential adsorption of the substances on the solid phase.
(C)Gravitational force.
(D)Capillary action.

Q143·ChemistrySingle correctJEE Main 2019

The correct match between items I and II is:

Item – I (Mixture)	Item – II (Separation method)
a. $H_2O$ : Sugar	p.Sublimation
b. $H_2O$ : Aniline	q.Recrystallization
c. $H_2O$ : Toluene	r.Stem distillation
	s.Differential extraction

(A)a - d, b – r, c – p
(B)a – q, b – r, c – s
(C)a – r, b – p, c – s
(D)a – q, b – r, c – p

Q144·ChemistrySingle correctJEE Main 2019

An organic compound is estimated through Dumus method and was found to evolve 6 mole of

CO_2

, 4 moles of

H_2O

and 1 mole of nitrogen gas. The formula of the compound is:

(A) $C_{12}H_8N$
(B) $C_{12}H_8N_2$
(C) $C_6H_8N_2$
(D) $C_6H_8N$

Q145·ChemistrySingle correctJEE Main 2019

If dichloromethane(DCM) and water(H

_{2}

O) are used for differential extraction, which one of the following statements is correct?

(A)DCM and H $_{2}$ O would stay as lower and upper layer respectively in the S.F
(B)DCM and H $_{2}$ O will make turbid/colloidal mixture
(C)DCM and H $_{2}$ O would stay as upper and lower layer respectively in the separating funnel(S.F)
(D)DCM and H $_{2}$ O will be miscible clearly

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