Question

Which of the following properties are characteristic of lyophobic sols?
1. Low viscosity; 2. High viscosity; 3. Reversibility and 4. Coagulation by electrolytes at low concentration
Select the correct answer using the codes given below:

• A. 2,3 and 4
• B. 2 and 3 only
• C. 1 and 4 only
• D. 1 and 3 only

Answer 1

The correct option is C 1 and 4 only

The colloidal system in which the dispersed phase have no affinity for the dispersion medium are called lyophobic (solvent hating) colloids. They are easily precipitated (or coagulated) on the addition of small amounts of the electrolyte, by heating or by shaking. They are less stable and irreversible.

These have low viscosity, and are easily coagulated.