An emulsion is formed when two or more immiscible substances are united with the help of what?

• A. Heat and pressure
• B. A binder
• C. A surfactant
• D. A solvent

Answer: (B)

An emulsion forms when two immiscible liquids are stabilized so droplets of one phase stay dispersed in the other. The element that makes this possible is an emulsifier, often called a surfactant. It sits at the interface between the two liquids, lowers the interfacial tension, and coats the droplets to prevent them from coalescing, producing a stable mix of oil in water or water in oil.

A binder helps hold ingredients together and give structure, but it doesn’t create a stable emulsion by itself. Heat and pressure can aid mixing in some processes but aren’t the defining factor for forming an emulsion. A solvent dissolves substances into a uniform solution rather than creating dispersed droplets. So the key to forming a true emulsion is using a surfactant/emulsifier to stabilize the droplets.