Is there any type of oil that will sink? I was told by a college professor that there is, but he won't name it

Question

I know that oil and water do not mix because oil has a lower density than water. Can anyone tell me if there is any type of oil where the density is more than that of water.

Answer 1

Any material with greater density will sink in a fluid with less density. So the question is how to make the density of the oil greater or the density of the water lower.
First of all, you can choose an oil that has a higher density. Larger molecular weight compounds will generally have a higher density, and some oils may have suspended solids which will increase their density.

You may achieve success with some oils by using heat. As most materials heat up, their density decreases, but not necessarily at the same rate. If you choose an oil with a low coefficient of expansion, its density may stay close to its original value as the water's density decreases with heating. If you can get the water's density low enough before it boils, the oil will sink.

Answer 2

He was probably refering to oil wells - they're sunk!
But if he wasn't joking perhaps he was talking about ashphalt which is a heavy oil with mineral impurities. Very heavy fuel oils and tars are close to the density of water and at very low temperatures (when water becomes less dense and oil more dense) tar and heavy oil can sink.

Answer 3

I guess he means 'Bunker C' it's almost like tar.