Question

What is soap? How does it act in the cleansing of clothes?

Hint:

Soap cleans by forming micelles that trap dirt and grease, which are then washed away with water. The hydrophobic tails interact with oils and the hydrophilic heads interact with water.

Answer 1

Step 1: What is soap?
Soap is a type of surfactant, usually composed of fatty acid salts, which is used for cleaning. Soap molecules have two distinct parts:
- Hydrophilic (water-loving) head: This part is polar and interacts with water.
- Hydrophobic (water-hating) tail: This part is non-polar and interacts with oils and grease.
Soap is made by reacting fats or oils with an alkali, such as sodium hydroxide or potassium hydroxide, in a process called saponification. \[ \text{Fat/Oil} + \text{Alkali} \to \text{Glycerol} + \text{Soap (Fatty Acid Salt)} \] Step 2: How soap cleans clothes.
Soap molecules have the ability to remove dirt and grease from surfaces, like clothes, due to their dual nature. Here’s how the cleaning process works:
1. Attachment to dirt and oil: The hydrophobic tails of soap molecules attach to grease and oil particles present on the clothes. The hydrophilic heads face outward toward the water.
2. Formation of micelles: The soap molecules form structures called micelles, where the hydrophobic tails trap the oil and dirt particles inside, and the hydrophilic heads face outward in the water.
3. Washing away of dirt: The micelles formed around the dirt and oil are suspended in water, which allows them to be washed away, leaving the clothes clean.
Step 3: Conclusion.
Soap cleans clothes by forming micelles that trap and remove oil, grease, and dirt. The hydrophobic tail of the soap attaches to the dirt, while the hydrophilic head interacts with water to help wash it away.