Why are lipids insoluble in water?

Answer 1

== == Water molecules form hydrogen bonds with other water molecules because electrons are shared unequally between hydrogen and oxygen, in something called a polar bond. This is a result of oxygen's larger nucleus, which makes it attract electrons with more strength than the hydrogen atoms do (higher electronegativity), so that the electrons spend more time closer to the oxygen atom. The partial negative charge on the oxygen is then attracted to the partial positive charge on hydrogen atoms of other water molecules. This is the hydrogen bond, and it is energetically favourable. Fats are composed mostly of non-polar bonds (they have no elements with high electronegativity), which don't form hydrogen bonds. As a result the fat molecules do not interact well with water molecules, so they are 'repelled' by the water and do not dissolve.

More accurately, for water to dissolve fats, a large number of hydrogen bonds between water molecules would have to be broken. As this requires energy, it is not a favourable process. This makes it necessary for the water to adopt a cage structure, called a solvation shell, around each fat molecule, to minimise the unavoidable energy requirement. Unfortunately, this results in an unfavourable decrease in entropy (all systems aim to increase entropy). To minimise the loss in entropy, the fats will aggregate or lie on the surface of the water to reduce the surface area of contact between the fats and the water. This is the hydrophobic effect, and is the reason why fats are insoluble in water. Fats have lesser specific gravity than water. Thus, making it floaton water. But, if an emulsifying agent will be added to the medium, the surface tension will decrease cause for the two immiscible liquids to mix.

Answer 2

Lipids are basically fats and oils, neither of which are soluble in water. They are insoluble in water because their molecules are nonpolar and they arn't attracted by water molecules.

Answer 3

Because they're non-polar,and non-polar substances don't dissolve in water,they dissolve in petroleum,or other non-polar solvents.

Answer 4

Lipids aren't soluble(in water) because lipids are nonpolar and water is polar. The two can't mix.

Answer 5

If they were soluble they would mix with water.

Sugar or salt are soluble in water.

lipids are fats and they do not mix, they float because they are more boyant than water.

Answer 6

they are acids

Answer 7

They are hydrophobic.