Question

Whenever a mixture of gases is allowed to come in contact with a particular adsorbent under the same conditions, the more strong adsorbate is adsorbed to greater extent irrespective of its amount present. For example, $H_{2}O$ is adsorbed to more extent on silica gel than $N_2$ and $O_2$. This shows that some adsorbates are preferentially adsorbed. It is also observed that preferentially adsorbable adsorbents can displace a weakly adsorbed substance from the surface of an adsorbent.

Chromatogarphic separations are based on:

• A. differential solubility
• B. differential adsorption
• C. differential absorption
• D. None of these

Answer 1

The correct option is B differential adsorption

Chromatographic separations of mixtures of various compounds are based on their distribution between a stationary and a mobile phase, which is present in a chromatographic column. The mobile phase moves across the column, in effect washing (eluting) compounds at a different rate. These differences are based on properties such as the boiling point, the polarity, the electric charge (for ionic compounds), the size of the molecule, and so forth.