Question

which two properties of Petroleum makes it possible to form a separate layer over Water

Answer 1

The density of crude oil or petroleum is much less than that of water which is why it floats above water.

If we were to look at the density of water then it stands at 1000kg/Cu m however, when it comes to the density of crude oil or petroleum it ranges in between 870–920kg/cu.m.

Since the density of petroleum is obviously less therefore it floats on water.

Answer 2

Petroleum occurs deep inside the earth floating over water. It forms a seperate layer over water because of its two property-

1st. Its density is less than water

2nd. It is insoluble