If I pour a spoon of oil on a jar full of water no doubt it will float. But if I were to pour a spoon of water on a jar full of oil would it sink? Why or why not?
Provided the Oil is non polar, it is simply a question of Specific Gravity. If the specific gravity ( Term we use in the Oil Industry) or density is greater than 1 (one) the water will remain on the surface, if the Specific Gravity is less than 1 (one) the water will sink. If the specific gravity is 1, add some food coloring, some heat, and you have poor mans lava lamp. For reference Crude Oil can vary in SG from "1.5" or greater ( heavy ) to as light as "0.77". Oil Lighter than 0.77 or API Gravity of 50 is usually referred to as condensate.