Why in the News?
This newscard is an excerpt from the original article published in ‘The Hindu’.
About Soap:
- Composition: Soap is sodium (Na) or potassium (K) salt of fatty acids derived from vegetable oils or animal fats.
- Formula: Solid soaps are RCOONa, liquid soaps are RCOOK.
- Function: Cleansing agent due to dual hydrophilic (water-attracting) and hydrophobic (oil-attracting) nature.
- History: Used since 2800 BC in Mesopotamia and ancient India (soap nuts, bark, flowers). Became mass-produced during the Industrial Revolution, initially a luxury.
Soap-Making Process
- Raw Materials: Oils such as coconut, olive, palm, sunflower provide triglycerides.
- Hydrolysis: Oils hydrolysed with hot water under pressure → fatty acids + glycerin.
- Saponification: Fatty acids react with sodium hydroxide (NaOH) → soap (RCOONa) + water.
- Processing: Soap dried into noodles, blended with perfumes, colours, fillers, additives.
- Shaping: Extruded, cut, and stamped into bars.
- Quality: Total Fatty Matter (TFM) indicates quality; higher TFM = better cleansing.
- Production Scale: Modern automated lines make 600–700 soaps per minute.
Ecological Impact of Soap
- Biodegradability: Traditional soaps are biodegradable and safer for the environment.
- Detergents: Synthetic alternatives developed during World War I oil shortages; more efficient but harmful.
- Pollution: Surfactants and phosphates in detergents cause nutrient pollution and persist in ecosystems.
| [UPSC 2002] Consider the following statements:
Assertion (A) Synthetic detergents can lather well in hard water. Reason (R): Synthetic detergents form soluble calcium and magnesium salts with hard water. Which one of the following is correct in respect of the above statements? Options: (a) Both A and R are individually true and R is the correct explanation of A * (b) Both A and R are individually true but R is not a correct explanation of A (c) A is true but R is false (d) A is false but R is true |
