Practical Organic Chemistry
128 Questions
Start JEE Mains Test
2021
Q101
JEE Mains
Numerical
14 Mar 2026
0.8 g of an organic compound was analyzed 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 H2SO4 would have been neutralized by the ammonia evolved during the analysis.
Correct Answer: 12
Explanation:
Organic compound : 0.8 gm
wt. of N = $\left( {{{42} \over {100}} \times 0.8} \right)$ gm
mole of N = ${{{42 \times 0.8} \over {100 \times 14}} = {{2.4} \over {100}}}$ mol
moles of NH3 = ${{{2.4} \over {100}}}$
${{{1.2} \over {100}}}$ = 1 $\times$ V(l)
${ \Rightarrow {V_{{H_2}S{O_4}}} = {{1.2} \over {100}}l = 12}$ ml
wt. of N = $\left( {{{42} \over {100}} \times 0.8} \right)$ gm
mole of N = ${{{42 \times 0.8} \over {100 \times 14}} = {{2.4} \over {100}}}$ mol
moles of NH3 = ${{{2.4} \over {100}}}$
${{{1.2} \over {100}}}$ = 1 $\times$ V(l)
${ \Rightarrow {V_{{H_2}S{O_4}}} = {{1.2} \over {100}}l = 12}$ ml
2021
Q102
JEE Mains
Numerical
14 Mar 2026
Methylation of 10 g of benzene gave 9.2 g of toluene. Calculate the percentage yield of toluene __________. (Nearest integer)
Correct Answer: 78
Explanation:
${C_6}{H_6} + C{H_3}Cl\mathrel{\mathop{\kern0pt\longrightarrow}
\limits_{}} {C_6}{H_5}C{H_3} + HCl$
10 gm of C6H6 = ${{10} \over {78}}$ mole
Moles of methylbenzene should be obtained = ${{10} \over {78}}$ mole
= $\left( {{{10} \over {78}} \times 92} \right)gm $
$ \therefore $ ${{{A_y}} \over {{T_y}}} = \% $ yield $ = {{9.2} \over {920}} \times 78 \times 100 \Rightarrow 78\% $
10 gm of C6H6 = ${{10} \over {78}}$ mole
Moles of methylbenzene should be obtained = ${{10} \over {78}}$ mole
= $\left( {{{10} \over {78}} \times 92} \right)gm $
$ \therefore $ ${{{A_y}} \over {{T_y}}} = \% $ yield $ = {{9.2} \over {920}} \times 78 \times 100 \Rightarrow 78\% $
2021
Q103
JEE Mains
Numerical
14 Mar 2026
In the above reaction, 3.9 g of benzene on nitration gives 4.92 g of nitrobenzene. The percentage yield of nitrobenzene in the above reaction is ________%. (Round off to the Nearest Integer).
(Given atomic mass : C : 12.0 u, H : 1.0 u, O : 16.0 u, N : 14.0 u)
Correct Answer: 80
Explanation:
Weight of (C6H5NO2)Theoretical = ${{{3.9} \over {78}} \times 123}$ = 6.15 g
% yield of reaction = ${{{W_{actual}}} \over {{W_{theoretical}}}} \times 100 = {{4.92} \over {6.15}} \times = 80\% $
2021
Q104
JEE Mains
Numerical
14 Mar 2026
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]
Correct Answer: 19
Explanation:
Aqueous tension at 287 K = 14 mm of Hg.
Hence actual pressure = (758 – 14)
= 744 mm of Hg.
Moles of ${N_2} = {{\left( {758 - 14} \right)} \over {760}} \times {{30 \times {{10}^{ - 3}}} \over {0.0821 \times 287}}$
$ = 1.246 \times {10^{ - 3}}$ mol
mass of ${N_2} = 1.246 \times {10^{ - 3}} \times 28$
mass % of N2 $ = {{mass\,of\,'N'} \over {total\,mass}} \times 100$
$ = {{1.246 \times 28 \times {{10}^{ - 3}}} \over {0.184}} \times 100$
$ = {{124.6 \times 28} \over {0.184}}\% = 18.96\% $
$ \simeq 19\% $
Hence actual pressure = (758 – 14)
= 744 mm of Hg.
Moles of ${N_2} = {{\left( {758 - 14} \right)} \over {760}} \times {{30 \times {{10}^{ - 3}}} \over {0.0821 \times 287}}$
$ = 1.246 \times {10^{ - 3}}$ mol
mass of ${N_2} = 1.246 \times {10^{ - 3}} \times 28$
mass % of N2 $ = {{mass\,of\,'N'} \over {total\,mass}} \times 100$
$ = {{1.246 \times 28 \times {{10}^{ - 3}}} \over {0.184}} \times 100$
$ = {{124.6 \times 28} \over {0.184}}\% = 18.96\% $
$ \simeq 19\% $
2021
Q105
JEE Mains
Numerical
14 Mar 2026
Consider titration of NaOH solution versus 1.25 M oxalic acid solution. At the end point following burette readings were obtained.
(i) 4.5 mL
(ii) 4.5 mL
(iii) 4.4 mL
(iv) 4.4 mL
(v) 4.4 mL
If the volume of oxalic acid taken was 10.0 mL then the molarity of the NaOH solution is ________ M. (Rounded off to the nearest integer)
(i) 4.5 mL
(ii) 4.5 mL
(iii) 4.4 mL
(iv) 4.4 mL
(v) 4.4 mL
If the volume of oxalic acid taken was 10.0 mL then the molarity of the NaOH solution is ________ M. (Rounded off to the nearest integer)
Correct Answer: 6
Explanation:
Average burette reading = Volume of NaOH solution (V1)
$ = {{4.5 + 4.5 + 4.4 + 4.4 + 4.4} \over 5}$
= 4.44 mL
Strength of NaOH solution = S1(M) (say) = S1(N)
Volume of oxalic acid solution (V2) = 10 mL
Strength of oxalic acid solution (S2) = 1.25 M = 1.25 $\times$ 2 N
So, ${V_1}{S_1} = {V_2}{S_2}$ ($\because$ Law of equivalence)
$ \Rightarrow {S_1} = {{{V_2}{S_2}} \over {{V_1}}} = {{10 \times (1.25 \times 2)} \over {4.44}} = 5.63$ N
$ \simeq 6M = 6M$
2021
Q106
AP-EAPCET
MCQ
20 May 2026
In Lassaigne’s test for halogens, it is necessary to remove X and Y from the sodium fusion extract, if nitrogen and sulphur are present. This is done by boiling the extract with Z. Identify X, Y and Z.
A.
$X=\mathrm{NaNO}_3, \quad Y=\mathrm{Na}_2 \mathrm{SO}_4, \quad Z= \mathrm{conc}. \mathrm{HNO}_3$
B.
$X=\mathrm{NaNH}_2, \quad Y=\mathrm{NaSH}, \quad Z= \mathrm{conc}. \mathrm{HCl}$
C.
$X=\mathrm{Na}_2 \mathrm{NO}_2, Y=\mathrm{NaSO}_3 \mathrm{H}, \quad Z= \mathrm{conc}. \mathrm{H}_2 \mathrm{SO}_4$
D.
$X=\mathrm{NaCN}, \quad Y=\mathrm{Na}_2 \mathrm{~S}, \quad Z= \mathrm{conc}. \mathrm{HNO}_3$
2020
Q107
JEE Mains
MCQ
14 Mar 2026
If you spill a chemical toilet cleaning liquid on
your hand, your first aid would be
A.
aqueous NaOH
B.
aqueous NaHCO3
C.
aqueous NH3
D.
vinegar
2020
Q108
JEE Mains
MCQ
14 Mar 2026
In Carius method of estimation of halogen,
0.172 g of an organic compound showed
presence of 0.08 g of bromine. Which of these
is the correct structure of the compound?
A.
H3C – CH2 – Br
B.
H3C – Br
C.
D.
2020
Q109
JEE Mains
MCQ
14 Mar 2026
A, B and C are three biomolecules. The results
of the tests performed on them are given
below:
$ \begin{array}{|l|l|l|l|} \hline & \begin{array}{l} \text { Molisch's } \\ \text { Test } \end{array} & \begin{array}{l} \text { Barfoed } \\ \text { Test } \end{array} & \begin{array}{l} \text { Biuret } \\ \text { Test } \end{array} \\ \hline \text { A } & \text { Positive } & \text { Negative } & \text { Negative } \\ \hline \text { B } & \text { Positive } & \text { Positive } & \text { Negative } \\ \hline \text { C } & \text { Negative } & \text { Negative } & \text { Positive } \\ \hline \end{array} $
A, B and C are respectively :
$ \begin{array}{|l|l|l|l|} \hline & \begin{array}{l} \text { Molisch's } \\ \text { Test } \end{array} & \begin{array}{l} \text { Barfoed } \\ \text { Test } \end{array} & \begin{array}{l} \text { Biuret } \\ \text { Test } \end{array} \\ \hline \text { A } & \text { Positive } & \text { Negative } & \text { Negative } \\ \hline \text { B } & \text { Positive } & \text { Positive } & \text { Negative } \\ \hline \text { C } & \text { Negative } & \text { Negative } & \text { Positive } \\ \hline \end{array} $
A, B and C are respectively :
A.
A = Lactose, B = Glucose, C = Albumin
B.
A = Lactose, B = Fructose, C = Alanine
C.
A = Lactose, B = Glucose, C = Alanine
D.
A = Glucose, B = Fructose, C = Albumin
2020
Q110
JEE Mains
Numerical
14 Mar 2026
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)
(Atomic mass, Ag = 108, Br = 80 g mol–1)
Correct Answer: 50
Explanation:
Mass of organic compound = 1.6 gm
Mass of AgBr = 1.88 gm
Moles of Br = Moles of AgBr = ${{1.88} \over {188}}$ = 0.01
Mass of Br = 0.01 × 80 = 0.80 gm
% of Br = ${{0.80 \times 100} \over {1.60}}$ = 50 %
Mass of AgBr = 1.88 gm
Moles of Br = Moles of AgBr = ${{1.88} \over {188}}$ = 0.01
Mass of Br = 0.01 × 80 = 0.80 gm
% of Br = ${{0.80 \times 100} \over {1.60}}$ = 50 %
2020
Q111
TS-EAMCET
MCQ
20 May 2026
Which one of the following methods is suitable to separate a mixture of $n$-pentane and toluene?
A.
Steam distillation
B.
Simple distillation
C.
Sublimation
D.
Vacuum distillation
2020
Q112
TS-EAMCET
MCQ
20 May 2026
During the course of estimating nitrogen using Kjeldahl's method, the organic compound is heated with
A.
conc. HCl
B.
dil. $\mathrm{H}_2 \mathrm{SO}_4$
C.
conc. $\mathrm{H}_2 \mathrm{SO}_4$
D.
conc. HI
2020
Q113
TS-EAMCET
MCQ
20 May 2026
Sodium fusion extract of aniline when heated with ferrous sulphate solution and then acidified with concentrated $\mathrm{H}_2 \mathrm{SO}_4$ from which of the following complexes?
A.
$\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{4-}$
B.
$\mathrm{Fe}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]_3 \cdot \times \mathrm{H}_2 \mathrm{O}$
C.
$[\mathrm{Fe}(\mathrm{SCN})]^{2+}$
D.
$\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NOS}\right]^{4-}$
2019
Q114
JEE Mains
MCQ
14 Mar 2026
An organic compound 'A' is oxidizod with Na2O2 followed by boiling with HNO3. 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:
Based on above observation, the element present in the given compound is:
A.
Fluorine
B.
Phosphorus
C.
Nitrogen
D.
Sulphur
2019
Q115
JEE Mains
MCQ
14 Mar 2026
The organic compound that gives following
qualitative analysis is :
| Test | Inference | |
|---|---|---|
| (a) | Dil. HCl | Insoluble |
| (b) | NaOH solution | soluble |
| (c) | Br2/water | Decolourization |
A.
B.
C.
D.
2019
Q116
JEE Mains
MCQ
14 Mar 2026
An organic compound neither reacts with neutral ferric chloride solution nor with fehling solution.
it however, reacts with Grignard reagent and gives positive iodoform test. The compound is :
A.
B.
C.
D.
2019
Q117
JEE Mains
MCQ
14 Mar 2026
An organic compound 'X' showing the following solubility profile is :
A.
o-Toluidine
B.
Benzamide
C.
Oleic acid
D.
m-Cresol
2019
Q118
JEE Mains
MCQ
14 Mar 2026
The correct match between item 'I' and item 'II' is :
| Item 'I' (compound) | Item 'II' (reagent) |
||
|---|---|---|---|
| (A) | Lysine | (P) | 1-naphthol |
| (B) | Furfural | (Q) | ninhydrin |
| (C) | Benzylalcohol | (R) | KMnO4 |
| (D) | Styrene | (S) | Ceric ammonium nitrate |
A.
(A) $ \to $ (Q); (B) $ \to $ (R); (C) $ \to $ (S);
(D) $ \to $ (P)
B.
(A) $ \to $ (Q); (B) $ \to $ (P); (C) $ \to $ (S);
(D) $ \to $ (R)
C.
(A) $ \to $ (R); (B) $ \to $ (P); (C) $ \to $ (Q);
(D) $ \to $ (S)
D.
(A) $ \to $ (Q); (B) $ \to $ (P); (C) $ \to $ (R);
(D) $ \to $ (S)
2019
Q119
JEE Mains
MCQ
14 Mar 2026
The tests performed on compound X and their inferences are :
Compound 'X' is :
| Test | Inference | |
|---|---|---|
| (a) | 2, 4 - DNP test | Coloured precipitate |
| (b) | Idoform test | Yellow precipitate |
| (c) | Azo-dye test | No dye formation |
Compound 'X' is :
A.
B.
C.
D.
2019
Q120
JEE Mains
MCQ
14 Mar 2026
The correct match between Item-I and Item-II is :
| Item-I (drug) | Item-II (test) | ||
|---|---|---|---|
| A | Chloroxylenol | P | Carbylamine test |
| B | Norethindrone | Q | Sodium hydrogen carbonet test |
| C | Sulphapyridine | R | Ferric chloride test |
| D | Penicillin | S | Bayer's test |
A.
A $ \to $ R; B $ \to $ P; C $ \to $ S; D $ \to $ Q
B.
A $ \to $ Q; B $ \to $ S; C $ \to $ P; D $ \to $ R
C.
A $ \to $ R; B $ \to $ S; C $ \to $ P; D $ \to $ Q
D.
A $ \to $ Q; B $ \to $ P; C $ \to $ S; D $ \to $ R
2018
Q121
JEE Mains
MCQ
14 Mar 2026
In a complexometric titration of metal ion with ligand
M(Metal ion) + L(Ligand) $ \to $ C(Complex) end point is estimated spectrophoto - metrically (through light absorption). If 'M' and 'C' do not absorb light and only 'L' absorbs, then the titration plot between absorbed light (A) versus volume of ligand 'L' (V) would look like :
M(Metal ion) + L(Ligand) $ \to $ C(Complex) end point is estimated spectrophoto - metrically (through light absorption). If 'M' and 'C' do not absorb light and only 'L' absorbs, then the titration plot between absorbed light (A) versus volume of ligand 'L' (V) would look like :
A.
B.
C.
D.
2018
Q122
JEE Mains
MCQ
14 Mar 2026
For standardizing NaOH solution, which of the following is used as a primary standard ?
A.
Ferrous Ammonium Sulfate
B.
dil. HCl
C.
Oxalic acid
D.
Sodium tetraborate
2018
Q123
JEE Mains
MCQ
14 Mar 2026
Which of the following compounds will be suitable for Kjeldahl’s method for nitrogen estimation?
A.
B.
C.
D.
2017
Q124
JEE Mains
MCQ
14 Mar 2026
Sodium salt of an organic acid ‘X’ produces effervescence with conc. H2SO4. ‘X’ reacts with the acidified
aqueous CaCl2 solution to give a white precipitate which decolourises acidic solution of KMnO4. ‘X’ is :
A.
CH3COONa
B.
Na2C2O4
C.
C6H5COONa
D.
HCOONa
2016
Q125
JEE Mains
MCQ
14 Mar 2026
Sodium extract is heated with concentrated HNO3 before testing for halogens because :
A.
Silver halides are totally insoluble in nitric acid.
B.
Ag2S and AgCN are soluble in acidic medium.
C.
S2− and CN−, if present, are
decomposed by conc. HNO3 and hence do not interfere in the test.
D.
Ag reacts faster with halides in acidic medium.
2011
Q126
JEE Mains
MCQ
14 Mar 2026
Which of the following reagents may be used to distinguish between phenol and benzoic acid ?
A.
Tollen’s reagent
B.
Molisch reagent
C.
Neutral FeCl3
D.
Aqueous NaOH
2010
Q127
JEE Mains
MCQ
14 Mar 2026
29.5 mg of an organic compound containing nitrogen was digested according to Kjeldahl’s method
and the evolved ammonia was absorbed in 20 mL of 0.1 M HCl solution. The excess of the acid
required 15 mL of 0.1 M NaOH solution for complete neutralization. The percentage of nitrogen in
the compound is
A.
59.0
B.
47.4
C.
23.7
D.
29.5
2004
Q128
JEE Mains
MCQ
14 Mar 2026
The compound formed in the positive test for nitrogen with the Lassaigne solution of an
organic compound is
A.
Fe4[Fe(CN)6]3
B.
Na4[Fe(CN)5NOS]
C.
Fe(CN)3
D.
Na3[Fe(CN)6]