Water is a great solvent of other polar or ionic substances. It is such a good solvent, it is called the universal solvent. Here is an animation showing how water dissolves the ionic sodium chloride NaCl.
The negative oxygen in water attracts the positive sodium ion and the hydrogen pulls the chlorine away. If water were not a polar molecule, could it dissolve NaCl?
Interactive popup. Assistance may be required. No. As a rule "like dissolves like." This saying means that polar solvents dissolve polar solutes. Non-polar solvents dissolve non-polar solutes. CloseOil is non-polar. Watch what happens in the video below when the oil and water are poured together.
The hosts of the video give you a lot of information about why you can move oil into one container and water into the other container. But they leave out a very important fact. Yes, the two liquids have different densities, but that doesn't explain completely why the two liquids do not mix at all. What do you suppose our hosts forgot to tell us?
Interactive popup. Assistance may be required. Because water is polar and oil is not polar the two do not mix. Close