Recall the principle of partition chromatography

In partition chromatography, separation occurs due to the different distribution of a solute between:

• a mobile phase, and
• a stationary liquid phase held on an inert support.

So, the basis is partition/equilibration between two phases, not adsorption on a solid surface.

Check each option

A: Mobile phase can be a gas

• True. In gas-liquid chromatography (GLC), the mobile phase is a gas and the stationary phase is a liquid.
• Hence, this statement is true.

B: Stationary phase is a finely divided solid adsorbent

• This describes adsorption chromatography, where the stationary phase is a solid adsorbent like silica or alumina.
• In partition chromatography, the stationary phase is a liquid supported on an inert solid.
• Hence, this statement is not true.

C: Separation depends upon equilibration of solute between a mobile and a stationary phase

• This is exactly the principle of partition chromatography.
• Hence, this statement is true.

D: Paper chromatography is an example of partition chromatography

• True. In paper chromatography, water adsorbed on cellulose acts as the stationary phase, and separation occurs by partition.
• Hence, this statement is true.

Conclusion

The statement which is not true about partition chromatography is: $\boxed{\text{B}}$

Comparison with stored correct answer

Stored correct answer: B

My derived answer: B

Therefore, the derived answer agrees with the stored correct answer.