What is Colloid?
A Colloid is a heterogeneous mixture whose particle size is intermediate between those of a solution and a suspension.
For example, a mixture of milk and water. The components of a colloid are:
● Dispersed phase
The solute-like component of the dispersed particles in a colloid forms the Dispersed phase.
● Dispersing medium
The component in which the dispersed phase is suspended is known as the Dispersing medium.
For example, in the milk and water mixture, milk is the dispersed phase and water is the dispersing medium.
The dispersed particles are spread evenly throughout the dispersion medium. These particles are extremely small and cannot be seen by the naked eye. The components in the colloid can be separated by a method called centrifugation but not by filtration.
What is the Tyndall effect?
The Tyndall effect is the scattering of visible light by colloidal particles.
When a beam of light is passed through the milk and water mixture, there is a scattering of light. The light is scattered by the particles of milk.
Tyndall effect
Another example of this effect is seen when rays of light that enter through the trees in a forest. The mist in the forest is also a colloid. The particles that are present in the mist scatter the beam of light.