Give an example each of:
(a) aerosol
(b) foam
(c) emulsion
(d) solid sol
Give an example each of:
(a) aerosol
(b) foam
(c) emulsion
(d) solid sol
Colloids: A colloid is a heterogeneous mixture in which the size of the particles is so small that the particles cannot be seen with the naked eye.
- The diameter of the particles of colloids lies in the range of 10-6 and 10-9 m.
- These particles can scatter a beam of light passing through them and make the path of light visible. This is known as the Tyndall effect.
- Dispersed phase: The phase which consists of the colloidal particles and present in the smaller quantity.
- Dispersion medium: The phase in which the particles are dispersed and is present in the larger quantity.
Based on the state of dispersed phase and dispersion medium, colloids are of various types:
(a) Aerosol: A type of colloid in which the dispersed phase can be a liquid or solid and the dispersion medium is gas.
- Liquid in gas type of aerosol: Aerosol in which dispersed phase is liquid and the dispersion medium is gas. Example: Fog, mist etc.
- Solid in gas type of aerosol or solid aerosol: Aerosol in which dispersed phase is solid and the dispersion medium is gas. Example: Dust-storm, smoke etc.
(b) Foam: A type of colloid in which the dispersed phase is a gas and the dispersion medium can be a solid or liquid.
- Gas in liquid type of foam: Foam in which dispersed phase is gas and the dispersion medium is liquid. Example: Shaving cream etc.
- Gas in solid type of foam: Foam in which dispersed phase is gas and the dispersion medium is solid. Example: Pumice stone, rubber, sponge etc.
(c) Emulsion: A type of colloid in which the dispersed phase is a liquid and the dispersion medium is also a liquid.
- Examples: Milk, face cream etc.
(d) Solid sol: A type of colloid in which the dispersed phase is a solid and the dispersion medium is also solid.
- Examples: Coloured gemstones, milky glass etc.
Colloids: A colloid is a heterogeneous mixture in which the size of the particles is so small that the particles cannot be seen with the naked eye.
- The diameter of the particles of colloids lies in the range of 10-6 and 10-9 m.
- These particles can scatter a beam of light passing through them and make the path of light visible. This is known as the Tyndall effect.
- Dispersed phase: The phase which consists of the colloidal particles and present in the smaller quantity.
- Dispersion medium: The phase in which the particles are dispersed and is present in the larger quantity.
Based on the state of dispersed phase and dispersion medium, colloids are of various types:
(a) Aerosol: A type of colloid in which the dispersed phase can be a liquid or solid and the dispersion medium is gas.
- Liquid in gas type of aerosol: Aerosol in which dispersed phase is liquid and the dispersion medium is gas. Example: Fog, mist etc.
- Solid in gas type of aerosol or solid aerosol: Aerosol in which dispersed phase is solid and the dispersion medium is gas. Example: Dust-storm, smoke etc.
(b) Foam: A type of colloid in which the dispersed phase is a gas and the dispersion medium can be a solid or liquid.
- Gas in liquid type of foam: Foam in which dispersed phase is gas and the dispersion medium is liquid. Example: Shaving cream etc.
- Gas in solid type of foam: Foam in which dispersed phase is gas and the dispersion medium is solid. Example: Pumice stone, rubber, sponge etc.
(c) Emulsion: A type of colloid in which the dispersed phase is a liquid and the dispersion medium is also a liquid.
- Examples: Milk, face cream etc.
(d) Solid sol: A type of colloid in which the dispersed phase is a solid and the dispersion medium is also solid.
- Examples: Coloured gemstones, milky glass etc.
