Question

Explain the method of preparation of soap

Answer 1

Soap is a combination of potassium or sodium salt of fatty acid. Hence, we can say it is made up of potassium or sodium salt and fatty acid which exist in nature. We use different kinds of soap for household purposes and to take baths that means we use combinations of different salts to make different kinds of soap.

Complete step by step answer:
Typically, soap is a fatty acid and as we said earlier there can be different fatty acids used such as stearic acid, palmitic acid and many more with a mixture of sodium or potassium salt. For laundry soap a high percentage of sodium is used and potassium salt is used for bathing soap. Acid supplies animal fat and vegetable oil for glycerol and ester compounds.
For preparing soap, sodium hydroxide is heated, glycerol and fatty acid produces sodium salt.
The preparation of soap is known as saponification.
Vegetable oil or animal oil $+$sodium hydroxide$\xrightarrow{{saponification}}$ glycerol $+$sodium salt of fatty acid
The mixture is heated at a certain temperature, after a while the soap forms a layer at the top and all the glycerin gets settled down. Then we take the glycerin out of it through the bottom part itself and the soap is collected from the above. Then it is cooled for a while.

Note: When oil or grease are mixed with soap and water, the soap molecule act as a bridge between polar and nonpolar water molecules. Soap molecules has nonpolar and polar molecules at two opposite ends