On the reasons for the immiscibility of ethyl acetate and water
The immiscibility of ethyl acetate and water is due to its molecular structure and properties.

The structure of ethyl acetate contains an ester group (-COO-). In this structure, the carbonyl group (C = O) has a certain polarity, but the alkyl group (-CH _ 2O _ CH) connected to the carbonyl group is a non-polar group. Overall, although ethyl acetate has a certain polarity, its polarity is relatively weak.

In contrast to water, its molecules are polar molecules, and the hydrogen atom and the oxygen atom are connected by covalent bonds. Because the electronegativity of oxygen is stronger than that of hydrogen, the hydrogen-oxygen bond has a strong polarity, and the water molecule becomes a very polar molecule.

The principle of chemistry is "similarity and dissolution". That is, substances with similar polarities are easy to dissolve with each other, and those with large polarity differences are difficult to dissolve with each other. Ethyl acetate has weak polarity and water has strong polarity. The polarity difference between the two is significant, and ethyl acetate is insoluble in water.

And from the intermolecular force, there is a hydrogen bond between water molecules, which is a strong intermolecular force. The intermolecular force of ethyl acetate is mainly van der Waals force, which is much weaker than the hydrogen bond. When ethyl acetate is mixed with water, the water molecules tend to maintain the hydrogen bond between themselves, and the ethyl acetate molecules also interact with van der Waals forces. The difference in the forces between the two molecules makes it difficult to intersperse and mix with each other, so it is insoluble.

In summary, the difference in molecular polarity and the difference in the forces between molecules are the fundamental reasons why ethyl acetate and water are insoluble.