Q.Explain the mechanism of cleansing action of soaps and detergents

Step 1. Section 15.3.1 explains the mechanism for soap using sodium palmitate: the hydrocarbon tail is non-polar/hydrophobic (dissolves in grease), the carboxylate head is polar/hydrophilic (dissolves in water).

Step 2. When soap contacts a greasy surface, the tails dissolve into the grease while the negatively charged heads stay exposed to water, which pulls the grease away as tiny droplets called micelles; the micelles stay separate because their surfaces, all carrying the same charge, repel one another.

Step 3. Rinsing then washes the micelles, and the dirt trapped in them, away with the water -- so soap acts as an emulsifying agent between water and water-insoluble grease. …

Walk through the dual-polarity mechanism for soap from 15.3.1 (tail into grease, head into water, micelle formation, rinse-away), then …

• Describing only soap's mechanism and forgetting to state that detergents work the same way …