Question

Which of the following can form iconic micelles in water?

• A. starch molecules
• B. sodium lauryl sulphate
• C. iodine molecules
• D. S₈ molecules

Answer 1

The Correct Option is B

The correct option is: (B): sodium lauryl sulphate.Sodium lauryl sulfate (SLS) is a surfactant commonly used in various personal care products, such as shampoos, soaps, and toothpaste. It has the ability to form iconic micelles in water due to its amphiphilic nature and molecular structure.

Iconic micelles are aggregates of surfactant molecules in a liquid, typically water, where the hydrophobic ("water-repellent") tails of the surfactant molecules cluster together in the center of the micelle, while the hydrophilic ("water-attracting") head groups face outward and interact with the surrounding water molecules.

Here's how sodium lauryl sulfate can form iconic micelles in water, justifying the answer:

Amphiphilic Nature: Sodium lauryl sulfate has both hydrophobic (long hydrocarbon chain) and hydrophilic (sulfate group) regions within its molecular structure. The hydrophobic tail of the molecule tends to avoid water, while the hydrophilic head group has an affinity for water.

Hydrophobic Interactions: When sodium lauryl sulfate molecules are introduced into water, their hydrophobic tails tend to aggregate together to minimize their contact with water. This results in the formation of spherical micelles, where the hydrophobic tails are shielded from the water, and the hydrophilic heads are exposed to the surrounding aqueous environment.

Stabilization: The repulsion between the hydrophilic head groups prevents the micelles from coalescing. The hydrophilic heads are oriented towards the water, ensuring stability and preventing the aggregation of micelles back into larger assemblies.

Solubilization: Iconic micelles can solubilize hydrophobic substances (such as oils and grease) within their hydrophobic cores, allowing these substances to be dispersed in water. This property is often utilized in cleaning products and personal care items to help remove dirt and oils from surfaces or skin.

In summary, sodium lauryl sulfate can form iconic micelles in water due to its unique molecular structure with hydrophobic and hydrophilic regions. The self-assembly of these molecules into micelles is driven by the desire to minimize the unfavorable interactions between the hydrophobic tails and water. This property is widely exploited in various consumer products for their cleaning, emulsifying, and foaming abilities.