Suspension Definition in Chemistry

A suspension is a type of heterogeneous mixture where solid particles are dispersed in a liquid or gas medium. These dispersed particles are relatively large and do not dissolve, meaning they remain suspended rather than truly mixing.

Key Characteristics of Suspensions

• Heterogeneous Nature: Components are not uniformly distributed.
• Large Particle Size: Particles are typically larger than those found in colloids or true solutions (often visible to the naked eye or under a microscope).
• Settling: Due to gravity and particle size, suspended particles will eventually settle out if left undisturbed.
• Opaque Appearance: Suspensions often appear cloudy or opaque because the large particles scatter light.
• Separation: Particles can usually be separated by simple filtration.

Analysis of Options

• A. A heterogeneous mixture with large particles: This aligns perfectly with the definition and characteristics of a suspension. The particles are visible, don't dissolve, and will settle.
• B. A colloidal dispersion: Colloids have smaller dispersed particles than suspensions, which do not settle out easily and are stable.
• C. A homogeneous mixture: In homogeneous mixtures (like solutions), components are uniformly distributed, and particles are molecularly dispersed.
• D. A true solution: True solutions have very small solute particles dissolved completely in the solvent, appearing uniform throughout.

Conclusion

Based on the definition, a suspension is characterized by its heterogeneous nature and the presence of large, undissolved particles that can settle out. Therefore, option A is the correct description.