MEDIUM
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Which technique is used for purification of solid organic compounds? (Crystallisation/Distillation).

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Important Questions on Organic Chemistry- Some Basic Principles and Techniques

EASY

Given below are two statements:
Statement-I: Retardation factor Rf can be measured in meter/centimetre.

Statement-II: Rf value of a compound remains constant in all solvents.

Choose the most appropriate answer from the options given below:

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

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:

EASY
The distillation technique most suited for separating glycerol from spent - lye in the soap industry is:
MEDIUM
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:
EASY
Which of the following processes for refining of metals involves a principle of selective adsorption of the components from a mixture.
MEDIUM
The elution sequence of a mixture of compounds containing chlorobenzene, anthracene and p -cresol developed from an alumina column using a solvent system of progressively increasing polarity is
EASY
Aniline is insoluble in water and possesses a vapour pressure of 10.15 mmHg at 373 K. It can be conveniently purified by
MEDIUM
The most suitable method of separation of 1:1 mixture of ortho and para-nitrophenol is:
MEDIUM
The correct match between items of List-I and List-II is
 
  List - I   List - II
(A) Coloured impurity (P) Steam distillation
(B) Mixture of o – nitrophenol and p –nitrophenol (Q) Fractional distillation
(C) Crude Naphtha (R) Charcoal treatment
(D) Mixture of glycerol and sugars (S) Distillation under reduced pressure
MEDIUM

Using the provided information in the following paper chromatogram:

Question Image

The calculated Rf value of A is _____×10-1.

HARD
A solution of m- chloroaniline, m- chlorophenol, and m- chlorobenzoic acid in ethyl acetate was extracted initially with a saturated solution of NaHCO3 to give fraction A . The leftover organic phase was extracted with a dilute NaOH solution to give a fraction B . The final organic layer was labelled as a fraction C . Fractions A,B and C, contain respectively:
EASY
Which of the following statements is not true about partition chromatography?
EASY
If Dichloromethane (DCM) and water H2O are used for differential extraction, which one of the following statements is correct?