Which of the following is not an example of associated colloids?

Gum

The correct answer is option 3. Gum.

The following is not an example of associated colloids: Gum

Associated colloids: These are colloids formed by the aggregation of molecules (amphiphiles) that have both hydrophilic (water-loving) and hydrophobic (water-fearing) parts. When these molecules are present in a solvent at a certain concentration (critical micelle concentration), they form micelles or other aggregates. Examples include:

Sodium stearate: A soap that forms micelles in water, making it an associated colloid.

Potassium stearate: Similar to sodium stearate, it is a soap that forms micelles in water.

Detergents: These are typically amphiphilic molecules that form micelles in water.

Gum: Gums are natural polymers that dissolve in water to form viscous solutions or gels, acting as lyophilic colloids. They do not form micelles or other associated structures like amphiphilic molecules do. Instead, they form colloidal dispersions due to their high molecular weight and solubility in water.

Therefore, gum is not an example of associated colloids, as it does not form micelles or aggregates like sodium stearate, potassium stearate, and detergents.