Question

Why does salt dissolve in water and not oil?

Answer 1

I get that water has a charge, and parts of salt have charges too, while oil doesn't have a charge. But oil had a single layer of phospholipid, and phospholipids have charged heads. Why can't the heads surround the salt?

Answer 2

The difference is that a phospholipid has only a negatively charged head and not a positive head. It has a polar and nonpolar part, but not a positive and negative part like a water molecule does. Oxygen is highly electronegative and hydrogen forms hydrogen bonds that are responsible for helping to pry apart the ionic bonds between salts. So although it is able and likely to have the heads near the positive end of the salt, this isn't really as strong to dissolve that much of a salt.

Answer 3

I checked in with my bio teacher and he phospholipid heads have both positive and negative charge like water, which is why in a bilayer membrane the heads are sticking out toward the water and the non-charged legs are facing in. The difference with oil is that there are no legs, and only tails, so there's no charge whatsoever in the oil.

But thank you Kainui for contributing.