Question

In chromatography technique, the purification of compound depends on:

• A. Length of the column or TLC plate
• B. Mobility or flow of solvent system
• C. Physical state of the pure compound
• D. Solubility of the compound

Answer 1

Answer: (A), (B), (D)

Solubility of the compound

We know that,
The separation of components can be expressed in terms of retardation factor i.e., $R_f$ value:
$R_f=\frac{\text{Distance travelled by solute}}{\text{Disatance travelled by solvent}}$
Hence, we need to fix the length of the column or TLC plate so as to measure the distance travelled by solute or solvent.
During separation, the components of the mixture move up along with the solvent to different distances depending on their degree of adsorption and separation takes place. Hence, the separation is dependent upon mobility or flow of solvent. Solubility is the property of how well a component of the mixture dissolves in the mobile phase. Higher the solubility in the mobile phase, the faster the molecule will move through the column. Hence, chromatographic separation is dependent on solubility of the compound.