Question

How does the nonpolar character of oil molecules helps when removing oil from water using nets and floating barriers?

Answer 1

Have you never used a separating funnel?

Explanation:

The less dense (typically organic) phase lies atop an aqueous phase in which it is immiscible. The long chain oil molecules, whose principle intermolecular attraction is the dispersion force, cannot be effectively solvated by water.

Crude oil is typically slightly less dense than water, and it should float on water in the event of an oil spill.

Just as an aside, I once had a `500*mL` sep flask with a plastic stopcock that had never been used for chemicals, and used it for the express purpose to make the gravy when I was cooking a roast - i.e. drain the fat and roasting juices into a sep funnel, and the juice from the meat would collect in the bottom half, which of course you could drain off to a separate pan to make the gravy.