What is a soap?

What Is A Soap?

We all know and identify a soap as something that helps us wash stuff, but what actually is a soap? What is its chemical definition?

A soap, in essence, is the salt of a fatty acid. A soap molecule consists of a polar ionic hydrophilic end (“water-loving’ end) and a nonpolar, hydrophobic end (“water-hating” end). When soap is mixed with water, its molecules arrange themselves in the form of roughly spherical aggregates of 60 or so molecules. 

True’ soaps are produced by mixing animal fats or vegetable fats with a strongly alkaline solution, such as lye (usually sodium hydroxide) or potash (fertilizer potassium). As such, from a purely technical standpoint, most modern liquid soaps are not actually soaps.


Two equivalent images of the chemical structure of sodium stearate, a typical soap for domestic handwashing. (Photo Credit : Smokefoot / Wikimedia Commons)


(information credited to: Science ABC)


(Sea Moss Soap)