Here’s a explanation:
Coagulation in Colloid Chemistry
- Definition: Coagulation is the process where colloidal particles come together and settle out of the dispersion.
- Why it happens: Colloidal particles carry charges that repel each other, keeping them stable. When this repulsion is neutralized (for example, by adding ions), particles stick together and form larger clumps called coagulates.
- Result: The colloid becomes unstable and separates from the medium.
How Coagulation Can Be Induced
- Electrolytes: Adding salts can neutralize charges on colloid particles.
- Example: Adding common salt to a soap solution causes coagulation.
- Heating: Increases particle movement, helping them stick together.
- Mechanical agitation: Sometimes shaking can help particles collide and coagulate.
Example:
- Milk turning sour: Casein colloid in milk coagulates due to acids or enzymes.
- Purification: Gold sol can be coagulated by adding a few drops of sodium chloride.
Simple tip:
- Coagulation → colloid particles stick together → settle → colloid unstable