Colloids

Step 1: Structure of micelle. Hydrophobic tails face inward, hydrophilic heads face outward.
Step 2: Reason. This minimizes interaction of non-polar part with water.

Step 1: Coagulation agents.
Coagulation is the process of removing suspended particles from water. The most effective agents are those that have a high charge density, such as .
Thus, the correct answer is (1).

Step 1: At isoelectric point, net charge on colloidal particles is zero.
Step 2: Hence no migration occurs in electric field.

Step 1: Sulphur sol is negatively charged.
Step 2: Higher valency cations are more effective (Hardy–Schulze rule).

Sulphur sol is negatively charged; coagulation is most effective with highest valency cation (Fe³+).

Step 1: Understanding the Concept:
Colloidal particles carry an electric charge. When a colloidal particle is in a medium, it develops a double layer of charges (the Helmholtz double layer) consisting of a fixed layer and a diffused layer.

Step 2: Detailed Explanation:
The potential difference between the fixed layer and the diffused layer of opposite charges is called the Zeta potential or electrokinetic potential. It is a measure of the magnitude of the electrostatic repulsion or attraction between particles and is one of the fundamental parameters known to affect stability.

Step 3: Final Answer
Zeta potential is directly related to the charge on the surface of colloidal particles.