State the different types of colloids with examples.

Introduction

Examples of colloids are the combination of two substance containing minute particles mixed with other substances. The embedded particle is considered as dispersion medium and the other substance like liquid, gas, or solid is considered as dispersion phase.

For example: Fog, here water is dispersion phase and gas is dispersion medium. Thus we can classify the colloids on basis of its dispersion phase and dispersion medium.

Classification of Colloids

The colloids get classified as sol, gel, emulsion, foam, and aerosol depends on their dispersion medium and dispersion phase.

• Sol- Colloids contains solid dispersion phase and liquid dispersion medium.

• Gel- Colloids contains liquid dispersion phase and solid dispersion medium.

• Emulsion- Colloids contains two liquids as dispersion phase and dispersion medium.

• Foam- Colloids contains gas as dispersion phase and liquid as dispersion medium.

• Aerosol- Colloids contain solid or liquid as dispersion phase and gas as dispersion medium.

• Hydrocolloids- Colloids contains the water as dispersion medium.

Basic characteristics of Colloids

• Colloidal particles are very tiny particles and ranges in nanometers.

• Colloidal substance is thick and dense in nature.

• Colloidal solutions cannot get separated by filtration.

• Tyndall effect use to show course of light which scatter and reflects.

• Brownian motion can be seen in colloidal particles.

• Colloidal particles can be separated from solution only through centrifugation process.

Figure 1: Important properties of colloids

Examples of Colloids

• Fog- Fog is a natural colloid and has liquid dispersed phase with gas dispersion medium.

• Smoke- Smoke is a natural colloid with solid dispersed phase and gaseous dispersion medium.

• Smog- Smog is natural colloid with liquid dispersed phase and gaseous dispersion medium.

• Milk- Milk is natural colloid with liquid as dispersed phase and dispersion medium.

• Pigmented plastic- pigmented plastic is man-made colloid with solid as dispersed phase and dispersion medium.

• Dust in air- Dust in air is natural colloid with solid dispersed phase in gaseous dispersion medium.

• Mayonnaise- Mayonnaise is a man-made colloid with liquid as dispersion phase and dispersion medium.

• Sprays- Sprays is a man-made colloid with liquid dispersion phase in gaseous dispersion medium.

• Sol of silver iodide- Sol of silver nitrate is man-made colloid with solid dispersion phase in liquid dispersion medium.

• Toothpaste- Toothpaste is a man-made colloid with solid dispersion phase in liquid dispersion medium.

• Whipped cream- Whipped cream is man-made colloid with gas dispersed phase in liquid dispersion medium.

• Pumice stone- Pumice stone is a natural colloid with gas dispersed phase in solid dispersion medium.

• Cloud- Cloud is a natural colloid with liquid dispersed phase in gaseous dispersion medium.

• Jelly- Jelly is a man-made colloid with liquid dispersed phase in solid dispersion medium.

• Cream- Cream is a man-made colloid with liquid dispersion phase in liquid dispersion medium.

• Haze- Haze is a natural colloid with solid dispersion phase in gas dispersion medium.

• Mist- Mist is a natural colloid with liquid dispersed phase in gaseous dispersion medium.

• Rubber- Rubber is a man-made colloid with gas dispersed phase in solid dispersion medium.

• Soap lather- Soap lather is a man-made colloid with gas dispersed phase in liquid dispersion medium.

• Curd- Curd is a man-made colloid with liquid dispersed phase in solid dispersion medium.

• Sol of gold- Sol of gold is man-made colloid with solid dispersed phase in liquid dispersion medium.

• Cheese- Cheese is a man-made colloid with liquid dispersed phase in solid dispersion medium.

• Colored glass- Colored glass is a man-made colloid with both solid dispersed phase and dispersion medium.

• Sulphur Sol- Sulphur sol is a man-made colloid with solid dispersed phase in liquid dispersion medium.

• Gems- Gems are natural colloid with both solid dispersion phase and dispersion medium.

• Butter- Butter is a man-made colloid with liquid dispersed phase and solid dispersion medium.

• Ruby glass- Ruby glass is a man-made colloid with both solid dispersed phase and dispersion medium.

• Gelatin- Gelatin is a man-made colloid with liquid dispersed phase in solid dispersion medium.

• Starch solution- Starch solution is man-made colloid with liquid dispersed phase in solid dispersion medium.

• Pearl- Pearl is a natural colloid with solid dispersion phase in liquid dispersion medium.

• Blood- Blood is a natural colloid with liquid dispersed phase in solid dispersion medium.

• Marshmallows- Marshmallow is a man-made colloid with gas dispersed phase and solid dispersion medium.

• Lava- Lava is a natural colloid with gas dispersed phase in solid dispersion medium.

• Paints- Paint is a man-made colloid with solid dispersed phase in liquid dispersion medium.

• Oil in water- Oil in water is man-made colloid with both liquid dispersion phase and dispersion medium.

Figure 2: Examples of colloids

Conclusion

Colloids are the combination or mixture of two substances with same or different state of matter. The one substance with which gets mixed with another substance is called dispersed phase and dispersion medium. Colloids are present in both particle and solution forms.

The particles size of colloidal particle ranges from 1 to 9 meters or 1 to 1000 nanometers. Colloids are of two types natural and man-made. Examples of natural colloids are cloud, lava, pearl, fog, gems, mist, haze, etc. Examples of man-made colloids are cheese, paints, marshmallows, toothpaste, curd, etc.

FAQs

Q1. What are colloids?

Ans. Colloids are the mixture of two substances of same or different state of matter like solid, liquid or gas. The colloids can be natural or man-made.

Q2. What is dispersion phase and dispersion medium?

Ans. The phase of colloid in which the particles are distributes is called dispersed phase and the medium to which the particles get added is called dispersion medium.

Q3. What is the size of particles present in colloidal substances?

Ans. The colloidal substance contains the particles of size ranges from 1 to 9 meters or 1 to 1000 nanometers.

Q4. Differentiate the following colloids as they are natural or man-made: Cloud, milk, rubber, mist, dust, sprays, fog, curd, paint, and toothpaste.

Ans. Natural colloids are: Cloud, milk, mist, dust, and fog. Man-made colloids are: Rubber, sprays, curd, paint, and toothpaste.

Q5. Define: Aerosol, sol, emulsion, and gel.

Ans. Aerosol: Aerosols are the colloids contains liquid or solid dispersion phase in gas dispersion medium.

Sol: Sol is the colloids contains solid dispersion phase in liquid dispersion medium.

Emulsion: Emulsion is the colloid with both liquid dispersion phase and dispersion medium.

Gel: Gel is a colloid with liquid dispersion phase and solid dispersion medium.