The polarity of ethyl ester and acetone
Ethyl ester and acetone are both common solvents in organic chemistry, and their polarity characteristics have a significant impact on many chemical processes.

Looking at the molecular structure, the structure of ethyl ester is $CH_3COOCH_2CH_3 $, and it contains an ester group. In this ester group, carbonyl C = O $has strong electron absorption, which makes the electron cloud biased towards oxygen atoms. However, the electron supply effect of ethoxy $- OCH_2CH_3 $slightly reduces the electron shift of carbonyl groups.

The structure of acetone is $CH_3COCH_3 $, and carbonyl C = O $. Due to the presence of methyl groups on both sides, methyl groups have a certain degree of electron conductivity. However, compared with ethoxy groups in ethyl esters, the electron conductivity of acetone is weaker, so the degree of carbonyl electron cloud offset of acetone is more significant than that of ethyl esters.

Usually, the polarity can be judged according to the dipole moment of the molecule. Acetone has a larger dipole moment than ethyl ester due to the large deviation of the carbonyl electron cloud, that is, the polarity is stronger. In terms of solubility, acetone can be miscible with water in any ratio, and the strong polarity makes it possible to form hydrogen bonds between acetone and water molecules. Although ethyl esters are also polar, the existence of ethoxy groups makes their ability to form hydrogen bonds with water molecules inferior to acetone, and their solubility in water is limited.

In the field of chromatographic analysis and other fields, the difference in polarity is also reflected. Due to the strong polarity of acetone, the retention ability of polar compounds is stronger; the polarity of ethyl ester is slightly weaker, and the retention ability of non-polar or weakly polar compounds is relatively better.

In short, the polarity of acetone is stronger than that of ethyl ester. This difference makes the two useful in many chemical fields such as organic synthesis, separation and analysis, and plays a unique role.