Step-by-step explanation:
Saponification is the process used for the production of the soap molecules via the hydrolysis of the triglyceride lipids .
The fat molecules used for the process is an ester of one molecule of glycerol (a triol) with three molecules of long-chain carboxylic acids i.e. , the fatty acids .
The use of Sodium hydroxide is to hydrolyze the ester bond and produce the sodium salts of the corresponding fatty acids in the fat , which are important for the soap molecules .
For the hydrolysis process , any strong base can be used but if an acid were to be used, a fatty acid rather than its salt will result and only fatty acid salts have a polar head and a non-polar tail which makes them soap . NaOH being cheap and readily available in most laboratories is preferred .