Cooking oil and vinegar dont mix why does the cooking oil stay on top of the vinegar?

Answer 1

The cooking oil is less dense than the vinegar - thus the cooking oil floats on the vinegar.

First of all, the above answer does not quite explain it. Even when two substances have different densities, they will often MIX, forming a mixture or solution. The fact that oil and vinegar do not mix is due to two things. First, "vinegar" is mostly water (about 95%), with a small amount of acetic acid and other substances in solution. The other factor here is that oils are "hydrophobic", meaning that they chemically repel water. The most stable configuration for two liquids that repel each other in this way when combined together is for the lighter of the two liquids to float to the surface and stay there in a unified mass. Oil is lighter than water and therefore ends up on top. If we were talking about pure acetic acid instead of vinegar, the result might be very different, but I really don't know. To improve the answer above, the reason why oil and lipids are hydrophobic is because they are nonpolar while water is polar. Substances with different polarities don't mix, while substances of the same polarity will mix REGARDLESS of density.

Answer 2

Scientifically speaking, oil is not soluble in water because water is a polar solvent and oil is non-polar. The term "polar" refers to an asymetrical molecue which has a negative end and a positive end.

Answer 3

Oil and vinegar in this case the vinegar will separate because of the difference in the polarity of water in the vinegar and the polarity of lipids in the oil. The water in the vinegar has polar molecules while the lipids in the oil have non-polar molecules. This means that it is very hard for water molecules to bind with oil molecules. In vinegar there is water and water is a polar molecule meaning it has two hydrogen atoms and one oxygen atom. Oxygen has 4 unshared electrons and they cause electro negativity and attract hydrogen atoms this means there is a positive side and a negative side to it.