JEE Main 2020
LEVELJEE Main
Visualized Solution
The Sigma Insight: Nomenclature and Characterisation
The Art of Separation
Imagine you are handed a flask containing a mixture of three different organic compounds dissolved in ethyl acetate.
Your mission is to separate them cleanly.
How do we achieve this? We use a powerful technique called acid-base extraction.
This method relies on a simple principle: converting water-insoluble organic compounds into water-soluble ionic salts.
Analyzing the Acidity
Before we start adding reagents, we must understand the chemical nature of our mixture.
We have -chlorobenzoic acid, -chlorophenol, and -chloroaniline.
Let's look at their acidic strengths.
-chlorobenzoic acid is a carboxylic acid, making it the strongest acid in our mixture.
-chlorophenol is a phenol, which is a weak acid.
Finally, -chloroaniline is an amine, which is actually a base.
The First Extraction
Fraction A
Our first step is to add a saturated solution of (sodium bicarbonate).
Sodium bicarbonate is a weak base.
Because it is weak, it can only react with strong acids.
Therefore, it will only deprotonate the -chlorobenzoic acid.
The resulting sodium -chlorobenzoate is an ionic salt, which is highly soluble in water.
It moves into the aqueous layer, which we collect as Fraction A.
The Second Extraction
Fraction B
Now, we are left with an organic layer containing -chlorophenol and -chloroaniline.
To separate these, we add a dilute solution of (sodium hydroxide).
Sodium hydroxide is a strong base.
It is powerful enough to deprotonate the weak acid, -chlorophenol.
The newly formed sodium -chlorophenoxide dissolves in the aqueous layer.
We collect this aqueous layer as Fraction B.
The Final Layer
Fraction C
What remains in our ethyl acetate organic layer?
Only the -chloroaniline is left behind.
Since it is a base, it does not react with the basic solution.
It remains completely un-ionized and stays dissolved in the organic solvent.
This final organic layer is our Fraction C.
Final Conclusion
By strategically using bases of different strengths, we successfully separated the mixture.
Fraction A contains -chlorobenzoic acid.
Fraction B contains -chlorophenol.
Fraction C contains -chloroaniline.
Therefore, the correct option is (c).
Similar Questions
JEE Main 2020
LEVELJEE Advanced
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)
(C), (A) and (B)
(B)
(A), (B) and (C)
(C)
(B), (C) and (A)
(D)
(B), (A) and (C)
JEE Main 2019
LEVELJEE Main
The correct match between items I and II is
(A)
(A) (Q); (B) (R); (C) (S)
(B)
(A) (Q); (B) (R); (C) (P)
(C)
(A) (S); (B) (R); (C) (P)
(D)
(A) (R); (B) (P); (C) (S)
JEE Main 2019
LEVELJEE Main
The organic compound that gives following qualitative analysis is
(A)
(B)
(C)
(D)
JEE Main 2019
LEVELJEE Main
The correct match between item 'I' and item 'II' is \begin{array}{clcl} \hline & \textbf{Item 'I'} & & \textbf{Item 'II'} \\ & \text{(Compound)} & & \text{(Reagent)} \\ \hline \text{(A)} & \text{Lysine} & \text{(P)} & \text{1-naphthol} \\ \text{(B)} & \text{Furfural} & \text{(Q)} & \text{Ninhydrin} \\ \text{(C)} & \text{Benzyl alcohol} & \text{(R)} & \text{KMnO}_4 \\ \text{(D)} & \text{Styrene} & \text{(S)} & \text{Ceric ammonium nitrate} \\ \hline \end{array}
(A)
(A) Q, (B) R, (C) S, (D) P
(B)
(A) R, (B) P, (C) Q, (D) S
(C)
(A) Q, (B) P, (C) S, (D) R
(D)
(A) Q, (B) P, (C) R, (D) S
JEE Main 2021
LEVELJEE Main
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 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
JEE Main 2014
LEVELJEE Main
For the estimation of nitrogen, of an organic compound was digested by Kjeldahl's method and the evolved ammonia was absorbed in of sulphuric acid. The unreacted acid required of sodium hydroxide for the complete neutralization. The percentage of nitrogen in the compound is
(A)
(B)
(C)
(D)
JEE Main 2019
LEVELJEE Main
An organic compound X showing the following solubility profile is
(A)
-toluidine
(B)
oleic acid
(C)
-cresol
(D)
benzamide
JEE Main 2019
LEVELJEE Main
If dichloromethane (DCM) and water () are used for differential extraction, which one of the following statements is correct?
(A)
DCM and would stay as lower and upper layer respectively in the S.F.
(B)
DCM and would stay as upper and lower layer respectively in the separating funnel (SF)
(C)
DCM and will be miscible clearly
(D)
DCM and will make turbid/colloidal mixture
JEE Advanced 2022
LEVELJEE Advanced
Match the compounds in LIST-I with the observation in LIST-II, and choose the correct option.
JEE Main 2021
LEVELJEE Main
Ceric ammonium nitrate and /alc. KOH are used for the identification of functional groups present in ......... and ......... respectively.
(A)
alcohol, phenol
(B)
amine, alcohol
(C)
alcohol, amine
(D)
amine, phenol