3 Differences between Solutions, Colloids, and Suspensions, What Are They?

Illustration of a solution in a disperse system (photo: Pixabay/Republica)

YOGYAKARTA - The difference between solutions, colloids, and suspensions is one of the chemistry subjects that is often discussed, both at the high school and university levels.

The terms solution, colloid, and suspension often appear in the discussion of dispersion systems and are often considered the same by some students.

In fact, solutions, colloids, and suspensions have different characteristics, both in terms of particle size, mixture properties, and stability.

By understanding the meaning, characteristics, and examples of each of these dispersion systems, students will find it easier to correctly classify a mixture into the categories of solution, colloid, or suspension.

Understanding of Solutions, Colloids, and Suspensions

Solutions, colloids, and suspensions belong to the dispersion system, i.e., a chemical system consisting of a dispersing medium (liquid or gas) and dispersed particles dispersed therein.

Recalling the book Colloidal Solutions (2022) by Haqqi Annazili Nasution et al., solutions are defined as a homogeneous mixture between a solvent and a solute. The particles of the solute are so small that they cannot be distinguished, even with an ultra-microscope. Therefore, the solution appears clear and stable even if it is left for a long time.

Colloids are mixtures that lie between solutions and suspensions. Colloids are heterogeneous, but the particles are small enough to be evenly dispersed in their dispersing medium. Colloidal mixtures usually appear cloudy and stable, not easily settling.

Meanwhile, a suspension is a heterogeneous mixture with relatively large particle size. Particles in a suspension can be seen with a regular microscope and will settle if the mixture is left undisturbed.

Difference between Solution, Colloid, and Suspension

Based on the above understanding, the differences between solutions, colloids, and suspensions can be seen from the particle size, level of homogeneity, and ability of particles to settle or separate. To better understand it, see the following explanation:

Based on particle size

One of the main factors in distinguishing the three is the particle size:

Solutions have particle sizes less than 1 nm Colloids have particle sizes between 1-100 nm Suspensions have particle sizes greater than 100 nm

The larger the particle size, the more unstable the dispersion system.

Based on the level of homogeneity

Solution:

Homogeneous in nature Clear in appearance Cannot be filtered Particles are not visible with a microscope

Colloids:

Heterogeneous in nature. Viscous. Particles are evenly dispersed.

Suspension:

Heterogeneity of nature Large-sized particles Based on the ability of particles to settle or separate

The differences between solutions, colloids, and suspensions can be seen from the ability of particles to settle or separate.

Solution:

It does not separate if it is left alone It cannot be seen with an ultra-microscope It cannot be filtered

Colloids:

It does not separate if it is left alone Can be seen with an ultra-microscope Can not be filtered

Suspension:

Easily settles Separates if left alone Can be seen with a regular microscope Can be filtered with a regular filter

That's the explanation about the difference between solutions, colloids, and suspensions. Get other interesting news updates only at VOI.id.