Question

Give one example each of sol and gel.

Answer 1

Both gel and sol are types of particular colloidal solutions. Only solid state and liquid state are involved as dispersion medium and dispersed phase in the case of both sol and gel. If we compare colloids with solutions, then the dispersion medium is like a solvent and dispersed phase is like solute.

Complete answer:
- Sol and gel are both types of colloids. Any heterogenous mixture that contains particles equally distributed over the medium called dispersion medium. The diameter of particles of colloids is generally 1nm to 1000nm. Now, based on a combination of different dispersed phase and dispersion mediums, colloids are classified. Let’s see two of them Sol and Gels.

Sol :
When any solid particles are dispersed in a liquid phase as a medium, then the colloidal system is known as sol.
- As example paints and cell fluids contain colloids which are called sol. Paints we use to colour houses involve the small particles that are suspended in the liquid phase, so it can be categorized as sol. Same way cell fluids also contain red blood cells, white cells etc. so they are also called sol.

Gel :
If liquid particles are suspended in a solid medium making colloidal solution, then the colloid is called a gel.
- As an example, Cheese and jellies are gel types of colloid. In cheese some liquid particles are suspended in solid material which makes up the majority of fat.

Note: Do not get confused with other types of colloids available like aerosol, solid sol, emulsion and foam as they contain different dispersion mediums and different dispersed phases. Remember that true solutions are not colloids, we cannot characterize them as solid particles dispersed in liquid medium because particle size is too small and they also have interactions with the solution molecules that colloids do not have.