A chromatography column,packed with silica ge | vedclass

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Question

(B) In silica gel column chromatography,the stationary phase is polar (silica gel,$SiO_2$).Compounds are separated based on their polarity; the least

Vedclass · Accepted Answer

$(C), (A)$ and $(B)$

Vedclass · Answer

(B) In silica gel column chromatography,the stationary phase is polar (silica gel,$SiO_2$).Compounds are separated based on their polarity; the least polar compound elutes first,and the most polar compound elutes last.The polarity of the given compounds is determined by their dipole moments and hydrogen bonding capability:$1.$ Acetophenone $(Ph-CO-CH_3)$: Dipole moment $\approx 3.05 \ D$.$2.$ Benzanilide $(Ph-NH-CO-Ph)$: Dipole moment $\approx 2.71 \ D$ (has hydrogen bonding).$3.$ Aniline $(Ph-NH_2)$: Dipole moment $\approx 1.59 \ D$ (has strong hydrogen bonding with silica gel).However,considering the interaction with the polar stationary phase,the elution order depends on the strength of adsorption.Aniline,being a primary amine,interacts strongly with the acidic silanol groups of silica gel.Acetophenone is the least polar among the three.Thus,the elution order is $(C)$ (Acetophenone) followed by $(A)$ (Benzanilide) and finally $(B)$ (Aniline).

Item $I$	Item $II$
$a$. Benzaldehyde	$p$. Mobile phase
$b$. Alumina	$q$. Adsorbent
$c$. Acetonitrile	$r$. Adsorbate

Column-$I$ (Mixture of compounds)	Column-$II$ (Separation Technique)
$A$. $H_2O / CH_2Cl_2$	$I$. Crystallization
$B$. $\alpha$-tetralone / $p$-nitrophenol	$II$. Differential solvent extraction
$C$. Kerosene / Naphthalene	$III$. Column chromatography
$D$. $C_6H_{12}O_6 / NaCl$	$IV$. Fractional Distillation

Similar Questions

Identify the purification technique for the following mixtures:
$(i)$ Chloroform and aniline
$(ii)$ Impure acetone
$(iii)$ Impure aniline
$(iv)$ Chlorobenzene and bromobenzene

The correct match between Item $I$ and Item $II$ is

Item $I$ Item $II$

$a$. Benzaldehyde $p$. Mobile phase

$b$. Alumina $q$. Adsorbent

$c$. Acetonitrile $r$. Adsorbate

How do you perform the purification of the following?
$(i)$ The boiling point of liquid $X$ is $450 \ K$ and it decomposes at $400 \ K$ temperature.
$(ii)$ Mixture of $60 \% \ \text{Camphor}$ and $40 \% \ BaSO_4$.

Describe the crystallisation technique used for the purification of organic compounds.

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