What is the Difference Between Suspension and Colloid?

The main difference between a suspension and a colloid lies in the size of the particles and their separation behavior. Here are the key differences:

• Particle Size: In a suspension, the particles have a diameter of about 1000 nm (1.0 µm) and are visible under a microscope. In contrast, the particles in a colloid are smaller, having a size ranging from 1.0 to 1000 nm (1.0 µm).
• Separation: A suspension is a heterogeneous mixture, and the dispersed particles separate from the dispersing phase on standing. In contrast, the particles in a colloid do not separate on standing.
• Appearance: Suspensions are generally considered heterogeneous because the different substances in the mixture do not mix uniformly, and the dispersed particles can be separated from the dispersion medium by filtering. Colloids, on the other hand, are more uniform in appearance and cannot be separated by filtration.
• Examples: Common suspensions include paint, blood, and hot chocolate, which are solid particles in a liquid medium. Examples of colloids include fog and milk, which are more uniformly dispersed throughout the medium.

In summary, suspensions are heterogeneous mixtures with larger particles that settle out, while colloids are more uniformly dispersed mixtures with smaller particles that remain suspended in the medium.

Comparative Table: Suspension vs Colloid

Here is a table that compares the properties of suspensions and colloids:

A suspension is a heterogeneous mixture in which the particles are large enough to settle out if the mixture is left undisturbed. Suspensions are cloudy and opaque due to the large particles scattering light. On the other hand, a colloid is a heterogeneous mixture with smaller particles that do not settle out and remain uniformly dispersed throughout the mixture. Colloids are translucent, allowing light to pass through partially, and they display the Tyndall effect, where light is scattered by the colloidal particles.