Question

How do surfactants reduce the surface tension?

Answer 1

Hint:The word surfactant comes from the surface-active agent; they are amphiphilic and have the property to get absorbed by an air-water interface. At the interface, they place themselves in such a way that the hydrophobic part is in the air and the hydrophilic part is in water.

Complete step by step solution:
As surfactants get absorbed, they break these interactions. The forces of attraction among surfactant and water molecules are less than the force of attraction between two water molecules. In other words, when the surfactant is dissolved in water, they accommodate towards the surface so that the hydrophobic part is removed from an aqueous environment. Hence, they reduce the surface tension. Also reducing the surface tension of a liquid in which the surfactant is dissolved is the main purpose of surfactant. Thus, they can also be used in the food industry as cleaning and treating agents for food-contact surfaces.

Note: The main aim of the surfactant is to reduce the surface tension and stabilize the interface. In absence of surfactant washing laundry would be difficult and many of the dairy products would not exist. The surfactants are less likely to stick to themselves and more likely to interact with oil and grease.