The system can achieve a more stable, lower-energy state by minimizing the surface area of contact between oil and water, which is why they spontaneously separate into distinct layers. The "cage" of water molecules surrounding the oil is a fragile and restrictive structure.
Understanding Polar and Nonpolar Molecular Immiscibility
Water is a polar molecule, meaning it has an uneven distribution of electrical charge. This ubiquitous phenomenon, visible in everything from a salad dressing to an ocean oil spill, dictates why these two common liquids refuse to blend.
By clumping together, oil molecules release some of these water molecules, allowing them to return to a more disordered and higher-entropy state. To minimize this disruption, water molecules instinctively rearrange themselves into a more ordered, cage-like structure around the oil droplets.
Understanding Polar and Nonpolar Molecular Immiscibility
The oxygen atom hogs the shared electrons more strongly than the hydrogen atoms, creating a partial negative charge on the oxygen side and a partial positive charge on the hydrogen side. Water, being the quintessential polar solvent, excels at dissolving other polar substances, such as salt, sugar, and ethanol.
More About Why oil doesn't mix with water
Looking at Why oil doesn't mix with water from another angle can help expand the discussion and give readers a second clear paragraph under the same section.
More perspective on Why oil doesn't mix with water can make the topic easier to follow by connecting earlier points with a few simple takeaways.
