In the classification of matter, how is an emulsion different from a solution?

• A. An emulsion is a pure substance with a fixed composition, whereas a solution is always a heterogeneous mixture.
• B. An emulsion consists only of solids dissolved in liquids, whereas a solution consists only of gases dissolved in liquids.
• C. An emulsion is a suspension whose particles always settle out on standing, whereas a solution is a colloid that scatters light strongly.
• D. An emulsion is a colloid of liquid droplets dispersed in another liquid, whereas a solution is a homogeneous mixture at the molecular or ionic level.

Answer: (D)

Verified step by step guidance

1. Understand the classification of matter: Matter can be classified as pure substances or mixtures. Mixtures can be homogeneous (solutions) or heterogeneous (colloids and suspensions).
2. Define a solution: A solution is a homogeneous mixture where the solute is dissolved at the molecular or ionic level in the solvent, resulting in a uniform composition throughout.
3. Define an emulsion: An emulsion is a type of colloid where tiny droplets of one liquid are dispersed throughout another liquid, but the two liquids are immiscible (do not mix uniformly).
4. Compare the two: Solutions are homogeneous and do not scatter light significantly, while emulsions are heterogeneous on a microscopic scale and can scatter light due to the dispersed droplets.
5. Summarize the key difference: An emulsion is a colloid consisting of liquid droplets dispersed in another liquid, whereas a solution is a homogeneous mixture at the molecular or ionic level.