Topic 5

         

       

 

Comparison of Solutions, Suspensions, and Colloids

Solutions, suspensions, and colloids are all mixtures of two or more substances, but they differ in the size of their dispersed particles and their stability.

Solutions:

●     Particle size: Particles are extremely small (molecular or ionic level).

●     Visibility: Transparent or translucent.

●     Separation: Particles cannot be separated by filtration or centrifugation.

●     Stability: Stable over time.

●     Examples: Saltwater, sugar water, air.

Suspensions:

●     Particle size: Particles are relatively large (visible under a microscope).

●     Visibility: Opaque or cloudy.

●     Separation: Particles can be separated by filtration or centrifugation.

●     Stability: Unstable, particles tend to settle over time.

●     Examples: Muddy water, sand in water.

Colloids:

●     Particle size: Particles are intermediate in size between solutions and suspensions (colloidal size).

●     Visibility: Can be translucent or opaque, depending on the nature of the particles.

●     Separation: Particles cannot be separated by filtration but can be separated by ultrafiltration.

●     Stability: Relatively stable, but can be coagulated or flocculated under certain conditions.

●     Examples: Milk, fog, smoke.

Key Points:

●     Solutions, suspensions, and colloids are all mixtures.

●     The size of the dispersed particles distinguishes these types of mixtures.

●     Solutions have the smallest particles, suspensions have the largest, and colloids are in between.

●     Solutions are stable, suspensions are unstable, and colloids are relatively stable.

●     Filtration and centrifugation can be used to separate suspensions but not solutions or colloids.

●     Ultrafiltration can be used to separate colloids.