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

Identify the correct statements from the following:
$(i)$ Electromeric effect is a permanent effect.
$(ii)$ Hyperconjugation is a temporary effect.
$(iii)$ Fractional distillation is used to separate two liquids from a mixture if the difference in their boiling points is less.
$(iv)$ Different compounds are adsorbed on an adsorbent to different extents.

Fill in the blanks:
$1$. In formulas and reactions,the electron pair displacement is indicated by a curved arrow,and the single electron displacement is indicated by a ..........
$2$. There are more than .......... plates in the columns of fractional distillation.
$3$. Fractional distillation is used for the separation of liquids with a .......... difference in boiling points,and simple distillation is used for the separation of liquids with a .......... difference in boiling points.
$4$. The .......... technique is applied to separate different fractions of crude oil in petroleum.

From the figure of column chromatography given below,identify the incorrect statements.
$A.$ Compound '$c$' is more polar than '$a$' and '$b$'
$B.$ Compound '$a$' is least polar
$C.$ Compound '$b$' comes out of the column before '$c$' and after '$a$'
$D.$ Compound '$a$' spends more time in the column
Choose the correct answer from the options given below :-

Benzoic acid is an organic compound. Its crude sample can be purified by crystallisation from hot water. What characteristic differences in the properties of benzoic acid and the impurity make this process of purification suitable?

Chromatography is a valuable method for the separation,isolation,purification,and identification of the constituents of a mixture. It is based on the general principle of: