The Tyndall effect is shown by colloidal solutions like milk and starch solution, not by true solutions like salt solution or copper sulphate solution.

🌟 Quick Scoop: which solution show Tyndall effect?

If you shine a beam of light (like a torch or laser) through different mixtures, only some will make the path of light visible. Those are the ones showing the Tyndall effect.

1. What is the Tyndall effect?

  • The scattering of light by tiny particles in a mixture so that the light beam becomes visible.
  • It is a characteristic property of colloids (and some suspensions), not of true solutions.

Think of car headlights in fog at night – you can see the “beam” because fog droplets scatter the light.

2. Which solutions show Tyndall effect?

Among common school-level examples:

  • Milk – Yes, shows Tyndall effect (it is a colloidal solution of fat in water).
  • Starch solution – Shows Tyndall effect because it behaves as a colloid; a beam of light is visible through it.
  • Salt solution (salt in water) – Does not show Tyndall effect; it is a true solution with particles too small to scatter light.
  • Copper sulphate solution – Also a true solution, so it does not show Tyndall effect.

In many textbook-type questions like “Which of the following will show Tyndall effect: salt solution, milk, copper sulphate solution, starch solution?”, the correct answers are milk and starch solution.

3. True solution vs colloid (mini table)

Type of mixture Example Tyndall effect?
True solution Salt in water, copper sulphate in water No visible beam; particles too small.
Colloid Milk, starch solution, fog, dust in air Yes, visible light path due to scattering.
Data: milk and starch solution behave as colloids and show Tyndall effect, whereas salt and copper sulphate solutions are true solutions and do not.

4. Simple activity you can imagine

  • Take three glasses:
    1. Salt solution in water
    2. Starch solution in water
    3. Milk in water
  • Darken the room and pass a laser/torch beam through each glass.
  • You will see the beam clearly in starch solution and milk , but not in salt solution.

This small “experiment in your head” matches how the Tyndall effect is demonstrated in school labs and videos.

TL;DR

  • Tyndall effect is shown by colloidal solutions.
  • In typical exam options, the solutions that show Tyndall effect are milk and starch solution ; salt solution and copper sulphate solution do not show it.

Information gathered from public forums or data available on the internet and portrayed here.