Question

By which of the following processes colloidal sols are purified?

• A. Peptisation
• B. Coagulation
• C. Dialysis
• D. Flocculation

Hint:

Dialysis and ultrafiltration are standard methods used for purification of colloidal solutions.

Answer 1

The Correct Option is C

Step 1: Recall purification process.
Purification of colloidal sols involves the removal of impurities like electrolytes and small molecules.
Step 2: Analyze options.
- (A) Peptisation: Process of converting precipitate into colloidal sol, not purification.
- (B) Coagulation: Precipitation of colloids, not purification.
- (C) Dialysis: Correct, it removes soluble impurities by diffusion through a semipermeable membrane.
- (D) Flocculation: Causes aggregation of particles, not purification.
Step 3: Conclusion.
Thus, purification of colloidal sols is carried out by Dialysis.