Question

What is a Tyndall Effect? Write any two applications of tyndall effect.

Answer 1

Hint: A colloid is a phase separated mixture in which one substance is suspended throughout another substance. One of the most significant properties of colloids is the presence of Tyndall Effect. Tyndall effect occurs when light scattering particles are suspended inside a light transmitting medium.

Complete step by step answer:
Tyndall effect is a phenomenon which is responsible for the scattering of light in a colloid or very fine suspension. If you project a concentrated beam of light through a solution, you cannot see the beam of light passing through it. However, the light beam will be quite apparent when it passes through a colloid.

Tyndall effect is observed when light scattering particles are suspended inside a light transmitting medium. In that case, light gets scattered by the particles and reaches the observer’s eyes. That is why we can see the light beam inside the colloid.

The intensity of the scattered light depends on the following factors:
(a) Density of the colloidal particles
(b) Frequency of the incident light.

Applications:

Here are two applications of Tyndall effect:

(i) Tyndall effect can be used to determine whether a mixture is solution, colloid, or suspension. If you point a light beam towards the mixture it can have three possible scenarios:
If you cannot see the light beam inside the mixture then it is a clear solution.
If the light beam is clearly visible, then the mixture is a colloid.
If the intensity of light decreases after passing through a medium, or completely gets blocked, then the mixture is a suspension.
(ii) Tyndall effect is responsible for the visible light beam of headlights. Generally, the air can be considered to be colloid when the dust particle concentration is too much. When the headlight passes through the air, the light beam is clearly visible.

Note:
Another popular application of Tyndall effect is determining the particle size of aerosols. The scattering depends on the size of the particle size as well. Also the scattering depends on the wavelength of the light beam. That is why the scattering of blue light is much more than the red light. It is one of the reasons behind the blue eye colour.