What are examples of coarse dispersions?

• A. Solutions
• B. Gels
• C. Aerosols
• D. Suspensions/Emulsions

Answer: (D)

Coarse dispersions consist of relatively large dispersed particles that are easy to see and that tend to settle out under gravity, typically larger than about 1 micron. This size means there is a visible, separate dispersed phase within a continuous medium, and the system often requires stirring to keep it uniform.

Suspensions are solid particles dispersed in a liquid, while emulsions are droplets of one immiscible liquid dispersed in another immiscible liquid. Both have the large dispersed phase characteristic of coarse dispersions and show separation with time if not mixed.

A solution contains solute molecules dissolved at the molecular level with no distinct dispersed phase, so it isn’t a coarse dispersion. A gel is a solid-like network that traps liquid rather than containing discrete dispersed particles. Aerosols are droplets or particles dispersed in a gas, a different category from coarse liquid-in-liquid or solid-in-liquid dispersions.