Explain the mechanism of the cleaning action of soap

Surfactants (yellow) cause water to lose surface tension, which is what keeps water separate from other materials Have you ever seen a bead of water sitting on a surface? This is because water has a property called surface tension. This tension causes water to form a bead on the surface of things like glass or fabric. You can see surface tension at work by placing a drop of water onto a counter top. The drop will hold its shape and will not spread. In order to clean the dirt on our clothes, the water needs to be able to reach the surface. Water is able to get to the surface if surface tension is reduced. To do this, we use a group of chemicals called surface active agents, or surfactants. What is a surfactant? Surfactants change how water behaves. When a surfactant is added, the surface tension is reduced. Now water can spread out and wet the surface (e.g., clothes, dishes, counter tops) we are trying to clean. Now let’s look at what happens on the surface. Like a magnet has two ends, one end of the surfactant is attracted to water molecules while the other is repelled. Every surfactant has two ends. One end wants to be in water and the other does not. The water-fearing end is known as the hydrophobic end. Hydrophobic comes from two Greek roots, hydro- (meaning water) and -phobia (meaning fearing). Have you heard the phrase “oil and water don’t mix?” This is important here! The water-fearing end of the surfactant is made up of hydrocarbon chains. A hydrocarbon is a molecul...

Preventing the soil from being deposited again onto the surface cleaned. The soap or detergent accomplishes this by suspending the dirt in a protective colloid, sometimes with the aid of special additives. In a great many soiled surfaces the dirt is bound to the surface by a thin film of oil or grease. The cleaning of such surfaces involves the displacement of this film by the detergent solution, which is in turn washed away by rinse waters. The oil film breaks up and separates into individual droplets under the influence of the detergent solution. stains, such as egg, milk, and blood, are difficult to remove by detergent action alone. The proteinic stain is nonsoluble in water, adheres strongly to the fibre, and prevents the penetration of the detergent. By using If detached oil droplets and dirt particles did not become suspended in the detergent solution in a stable and highly dispersed condition, they would be inclined to Uncover the science behind how soap removes dirt In order to perform as detergents (surface-active agents), soaps and detergents must have certain chemical structures: their molecules must contain a hydrophobic (water-insoluble) part, such as a 3Na or ―SO 3Na (such as in fatty alcohol sulfate or alkylbenzene sulfonate), or a long ethylene oxide chain in nonionic Four groups of surface-active agents are distinguished: • Get a Britannica Premium subscription and gain access to exclusive content. History Use Soap has been known for at least 2,300 years. ...

Cleaning Action of Soap: A soap molecule consists of two dissimilar parts: (i) A short ionic part comprising the carboxylate salt, -COO - Na*. This is the polar end. This is water soluble (i.e., hydrophilic or water attracting) and, therefore, remains attached to water. (ii) A long hydrocarbon chain which is the non-polar end.This end hydrophobic (i.e., waterrepelling) and is soluble in oil and grease. When soap is dissolved in water, it forms a colloidal suspension. In this colloidal suspension, the soap molecules cluster together to form micelles and remain radially suspended in water with the hydrocarbon end towards the centre and the ionic end directedoutward. This is shown in the figure. The dirt particles always adhere to the oily or greasy layer present on the skin or clothes. When a dirty cloth is dipped into a soap solution, its non-polar hydrocarbon end of micelles attach to the grease or oil present in dirt and polar end remains in water layer. The mechanical action ofrubbing subsequently dislodges the oily layer from the dirtysurface shaping it into small globules. Astable emulsion of oil in water is formed. The emulsified oilor grease globules bearing the dirt cannow be readily washed with water.