Question

Column chromatography is useful in the separation of compounds. Using the theory behind the technique, explain how it works. Why do you think fluorene and 9-fluorenone where are the components of the mixture you attempted to separate?

Answer 1

The theory behind the technique indicates that the solute will be retained in more or less strength by the stationary phase depending on the magnitude of the intermolecular interactions between them. So, there is a competence between the interactions solid phase- solute and eluent (liquid phase)- solute. Changing the polarity of the eluent we can change the adsortion velocity of the solute, achieving seperate them by its subtle differences in the nature of the molecular interactions with solid phase and eluent phase.

As I mentioned this technique allows to separate compounds with subtle differences in molecular structure. They are also solids which have similar solubilities, so the option of separation by solubility differences is not possible, but the stationary phase is do able to achieve this separation, because there is a polar group in the 9-fluorenone which allows to differenciate from the non-polar fluorenone.