The polarity difference between silica gel and ethyl acetate

The polarity of silica gel and ethyl acetate is often studied by commentators.

Silica gel contains many silicon-oxygen bonds in its structure. Between silicon and oxygen, the electronegativity is different, and the oxygen has strong electronegativity, so the electron cloud is biased towards the oxygen atom, resulting in the polarity of the silicon-oxygen bond. And there are hydroxyl groups on the surface of the silica gel, and the polarity of the hydrogen-oxygen bond in the hydroxyl group is also quite strong. The synergy of many polar bonds makes the overall polarity of the silica gel show.

In contrast, the molecular structure of ethyl acetate contains ester groups. Although there are carbon-oxygen double bonds and carbon-oxygen single bonds in the ester group, compared with silica gel, the carbon in the carbon-oxygen double bond has certain electron-giving properties, which partially weakens the polarity difference between carbon and oxygen. And its overall molecular structure symmetry is higher than that of silica gel, which limits molecular polarity.

Therefore, according to common sense, the polarity of silica gel is stronger than that of ethyl acetate. The structural characteristics of silica gel make the polar bonds agglomerate, but the characteristics of ethyl acetate structure make its polarity inferior to silica gel. From this perspective, in the contest of polarity, silica gel is better than ethyl acetate.