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 $40 \% \ BaSO_4$.

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

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:

Steam distillation process cannot be used for purifying which of the following?

Which of the following statements about $TLC$ are correct?
$(i)$ Glycine is identified on $TLC$ plate due to its colour.
$(ii)$ Amino acids can be detected by spraying the $TLC$ plate with $Ninhydrin$ solution.
$(iii)$ The retardation factor $(R_f)$ is the ratio of the distance travelled by the solute to that of the solvent from the base line.
$(iv)$ Sodium chloride is commonly used as an adsorbent.

Explain the principle of paper chromatography.