Colloids can be classified based on the state of the dispersed phase (the particles that are spread) and the dispersion medium (the substance in which they are spread). Here’s a breakdown:
1. Solid in liquid (Sols)
- Solid particles dispersed in a liquid.
- Example: milk of magnesia, paint, blood.
2. Liquid in solid (Gels)
- Liquid particles dispersed in a solid.
- Example: jelly, cheese, agar.
3. Liquid in liquid (Emulsions)
- One liquid dispersed in another liquid.
- Example: milk, butter, mayonnaise.
4. Gas in liquid (Foams)
- Gas bubbles dispersed in a liquid.
- Example: whipped cream, soap lather.
5. Solid in gas (Aerosols: smoke)
- Solid particles dispersed in a gas.
- Example: smoke, dust in air.
6. Liquid in gas (Aerosols: mist)
- Liquid droplets dispersed in a gas.
- Example: fog, spray, perfume mist.
Simple tip:
- Look at what is dispersed (solid, liquid, or gas) and where it is dispersed (liquid, solid, or gas) to classify colloids.