Advertisements
Advertisements
प्रश्न
Write a note on the Tyndall effect.
Advertisements
उत्तर
- Tyndall observed that when light passes through a true solution, the path of light through it cannot be detected.
- However, if the light passes through a colloidal dispersion, the particles scatter some light in all directions and the path of the light through colloidal dispersion becomes visible to an observer standing at right angles to its path.
- The phenomenon of scattering of light by colloidal particles and making the path of light visible through the dispersion is referred to as the Tyndall effect and the bright cone of the light is called the Tyndall cone.
- The Tyndall effect is observed only when the following conditions are satisfied.
a. The diameter of the dispersed particles is not much smaller than the wavelength of light used.
b. The refractive indices of the dispersed phase and dispersion medium differ largely. - Significance of Tyndall effect:
a. It is useful in determining the number of particles in the colloidal system and their particle size.
b. It is used to distinguish between colloidal dispersion and true solution.
APPEARS IN
संबंधित प्रश्न
Write one difference in Multimolecular colloid and Associated colloid
Identify the dispersed phase and dispersion medium in the following colloidal dispersions.
- milk
- blood
- printing ink
- fog
Write Hardy-Sulze rules.
Explain Bredig’s arc method.
Draw labelled diagram Tyndall effect.
Froth and whipped cream are examples of ____________.
Mixing of two oppositely charged sols leads to ____________.
Froth is a colloidal solution of ____________.
Which of the following is multimqlecular colloid?
Freshly prepared precipitate sometimes gets converted to colloidal solution by ______.
A colloidal system having a solid substance as a dispersed phase and a liquid as a dispersion medium is classified as ______.
Gelatin which is a peptide is added in icecreams. What can be its role?
What happens when electric field is applied to colloidal solution?
On the basis of Hardy-Schulze rule explain why the coagulating power of phosphate is higher than chloride.
Why is \[\ce{Fe(OH)3}\] colloid positively charged, when prepared by adding \[\ce{FeCl3}\] to hot water?
Match the items of Column I and Column II.
| Column I | Column II |
| (i) Butter | (a) dispersion of liquid in liquid |
| (ii) Pumice stone | (b) dispersion of solid in liquid |
| (iii) Milk | (c) dispersion of gas in solid |
| (iv) Paints | (d) dispersion of liquid in solid |
Cloud is an example of
For coagulating 200 ml of arsenious sulphide sol, 10 ml of 1 m NaCl solution is required find out the flocculation value of NaCl.
Fog is a colloidal solution of ______.
The size of a raw mango shrinks to a much smaller size when kept in a concentrated salt solution. Which one of the following processes can explain this?
In which of the following, the Tyndall effect is not observed?
Smoke is an example of ______.
Starch is an example of which of the following type of colloid?
Identify positively charged sol from following.
