8664 Views
5544 Views
5801 Views
Colloids can be classified on:
1. The basis of physical state of dispersed phase and dispersion medium
Each of the dispersed phase and the dispersion medium can be a solid or liquid or gas. There are eight different combinations possible.
| # | Dispersed Phase | Dispersion Medium | Name | Example |
|---|---|---|---|---|
| 1 | Solid | Solid | Solid Sol | Coloured glass, alloys. gems. |
| 2 | Solid | Liquid | Sol | Paints, inks. white of egg, colloidal Au, |
| 3 | Solid | Gas | Aerosol | Smoke. dust. |
| 4 | Liquid | Solid | Gel | Curds, cheese, jelly, pudding. |
| 5 | Liquid | Liquid | Emulsion | Milk, butter. oil in water. |
| 6 | Liquid | Gas | Aerosol | Mist, fog, clouds. |
| 7 | Gas | Solid | Solid foam | Cake, bread, pumice stone. |
| 8 | Gas | Liquid | Foam | Soap lather, aerated water. |
A colloidal solution with both the components in the gaseous state is not possible as according to Grahams Law of diffusion, they form a homogeneous mixture.
2. Classification on the basis of appearance:
| # | Sol | Gel |
|---|---|---|
| 1 | When a colloidal solution appears a fluid, it is termed as sol. Sols are named after the dispersion medium. | When a colloid has a solid like rigid appearance it is called gel. The rigidity of a gel varies from substance to substance. Some substances may occur both as sols as well as gels. This depends upon the relative concentrations of the dispersed phase and dispersion medium. |
| 2 | For example when dispersion medium is water, they are called hydrosols, if dispersion medium is alcohol they are called alcosols and if it is benzene, they are called benzosols. | A gel is formed by interlocking of the dispersed phase particles. Gelatine dissolves in warm water to form a colloidal solution which sets into a gel. |
3. Classification on the basis of solvent affinity
| # | lyophilic Sol (solvent loving): | lyophobic sol (solvent hating): |
|---|---|---|
| 1 | When the dispersion medium exerts an attraction on the dispersed phase then we get lyophilic Sol (solvent loving). | When the attraction between the dispersion medium and the dispersed phase is very little then the sol is called lyophobic sol (solvent hating). |
| 2 | Examples of lyophilic (reversible) sols: Protein, starch, glue, gelatine and agar-agar give reversible colloidal system with water. Rubber in benzene is also a reversible colloidal system. | Typical examples of lyophobic sols (non-reversible): Metals, sulphur, sulphides, silver halides, egg albumen, silicic acid and ferric hydroxide give non-reversible colloidal systems with water. |
5840 Views
6623 Views
5938 Views
7318 Views
5117 Views
Shared publicly - 2019-08-23 00:00:00
Don’t want your columns to simply stack in some grid tiers? Use a combination of different classes for each tier as needed. See the example below for a better idea of how it all works.
Shared publicly - 2019-08-24 00:00:00
For grids that are the same from the smallest of devices to the largest, use the .col and .col-* classes. Specify a numbered class when you need a particularly sized column; otherwise, feel free to stick to
Shared publicly - 2023-02-28 11:09:52
this is
Shared publicly - 2023-02-28 10:48:10
gsgsg
Apply to join the passionate instructors who share their expertise and knowledge with the world. You'll collaborate with some of the industry's best producers, directors, and editors so that your content is presented in the best possible light..