Revision Course (Purification of Organic Compounds PYQ Quiz)

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 (a)   . (Nearest integer)

[Atomic mass : Silver = 108, Bromine = 80]

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

• 
• 
• 
• 

Given below are two statements :

Statement I : Retardation factor (R_f) can be measured in meter/centimeter.

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

Choose the most appropriate answer from the options given below :

• Statement I is true but statement II is false

• Statement I is false but statement II is true

• Both statement I and statement II are true

• Both statement I and statement II are false

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

• Solubility of the compound

• Mobility or flow of solvent system

• Physical state of the pure compound

• Length of the column or TLC plate

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 :

• Both Statement I and Statement II are true

• Both Statement I and Statement II are false

• Statement I is true but Statement II is false

• Statement I is false but Statement II is true

Using the provided information in the following paper chromatogram :

Fig : Paper chromatography for compounds A and B.

The calculated R_f value of A (a)   × 10^-1.

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 : ethylacelate (20:80), the sequence of obtained compounds is :

• (A), (B) and (C)

• (B), (A) and (C)

• (C), (A) and (B)

• (B), (C) and (A)

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

• fractional distillation, 3-methylpentane

• simple distillation, 3-methylpentane

• fractional distillation, isohexane

• simple distillation, isohexane

Glycerol is separated in soap industries by :

• Fractional distillation

• Distillation under reduced pressure

• Differential extraction

• Steam distillation

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

• 
• 
• 
•