If you shake oil and water and then let it stand, what is observed?

If you shake oil and water and then let it stand, what is observed?

• A. A homogeneous solution forms.
• B. Two layers form.
• C. They evaporate quickly.
• D. A suspension forms.

Answer: (B)

Two liquids that don’t mix form separate phases because oil and water are immiscible. When you shake them, you create a temporary dispersion of tiny oil droplets in water, but without any stabilizer those droplets tend to combine again and separate due to gravity and interfacial tension. Since oil is less dense than water, the oil collects as a distinct layer on top while the water remains below. This is the observable result after letting the mixture stand. Evaporation isn’t the characteristic observation here, and a suspension would involve solid particles dispersed in a liquid, not two immiscible liquids.

Two liquids that don’t mix form separate phases because oil and water are immiscible. When you shake them, you create a temporary dispersion of tiny oil droplets in water, but without any stabilizer those droplets tend to combine again and separate due to gravity and interfacial tension. Since oil is less dense than water, the oil collects as a distinct layer on top while the water remains below. This is the observable result after letting the mixture stand. Evaporation isn’t the characteristic observation here, and a suspension would involve solid particles dispersed in a liquid, not two immiscible liquids.