Which of the following colloidal systems correctly represent points A, B and C ?

Question

Accepted Answer

Option 3 is the correct answer because it accurately represents the colloidal systems for points A, B, and C as follows:

1. **A-Paints**: Paints are colloidal systems where solid particles are dispersed in a liquid medium. This type of colloid is known as a sol. In paints, the pigment particles are dispersed in a liquid binder, making them a classic example of a sol.

2. **B-Smoke**: Smoke is a colloidal system where solid particles are dispersed in a gas. This type of colloid is known as an aerosol. Smoke consists of tiny solid particles or liquid droplets suspended in air, fitting the definition of an aerosol.

3. **C-Cloud**: Clouds are colloidal systems where liquid droplets are dispersed in a gas. This type of colloid is also an aerosol. Clouds consist of tiny water droplets or ice crystals suspended in the air, making them a perfect example of an aerosol.

Now, let's explain why the other options are incorrect:

1. **Option 1 (A-Mist; B-Whipped cream; C-Dust fumes)**:
   - Mist is an aerosol, which is correct, but whipped cream is a foam (gas in liquid), not a colloidal system like smoke. Dust fumes are similar to smoke but are not typically referred to as a distinct colloidal system like clouds.

2. **Option 2 (A-Milk; B-Hair cream; C-Pumice stone)**:
   - Milk is an emulsion (liquid in liquid), hair cream is also an emulsion, and pumice stone is a solid foam (gas in solid). None of these match the colloidal systems described in Option 3.

3. **Option 4 (A-Coloured glasses; B-Wings of butterflies; C-butter)**:
   - Coloured glasses are solid sols (solid in solid), wings of butterflies involve structural coloration rather than a colloidal system, and butter is an emulsion (liquid in solid). These do not correspond to the colloidal systems in Option 3.

In conclusion, Option 3 is the correct choice because it accurately describes the colloidal systems of paints, smoke, and clouds, which are sol, aerosol, and aerosol, respectively.