Question

Tyndall effect would be observed in:

• A. solution
• B. solvent
• C. precipitate
• D. colloidal sol

Answer 1

Answer: (D)

colloidal sol

If a homogeneous solution is observed in the direction of light, it appears clear and when it is observed from a direction at right angles to the direction of the light beam, it appears perfectly dark.

But when a beam of light passes through colloidal solutions, it is scattered, the maximum scattered intensity being in the plane at right angles to the path of light. The path beam becomes visible. The effect was first observed by Faraday but was studied in detail by Tyndall and the effect is not commonly known as the Tyndall effect.

Hence, option D is correct.