MCQ Detailed View

The process of saponification is the basic chemical reaction behind soap making. In this process, triglycerides (fats and oils) are hydrolyzed by a strong base such as sodium hydroxide (NaOH) or potassium hydroxide (KOH). The products of this reaction are soap (the sodium or potassium salts of fatty acids) and glycerol as a by-product.

Chemically, triglycerides are esters of glycerol with three long-chain fatty acids. When treated with alkali, the ester bonds undergo hydrolysis. The fatty acid portions combine with sodium ions to form soap, while the glycerol backbone is released as a separate compound.

The reaction can be summarized as:

Fat/Oil (Triglyceride) + NaOH → Soap (Sodium salt of fatty acid) + Glycerol

Analyzing the options:

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  Methanol is not produced in saponification; it is not part of triglyceride structure.

  
  


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  Glycol (ethylene glycol) is a diol used in antifreeze, not related to soap making.

  
  


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  Glycerol (propane-1,2,3-triol) is the correct by-product. It is a three-carbon alcohol with three hydroxyl groups.

  
  


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  Sodium hydroxide is a reactant in the process, not a by-product.

  
  

Glycerol obtained from saponification is an important industrial compound. It is used in the pharmaceutical industry, cosmetics, food industry (as a humectant and sweetener), and in the manufacture of explosives such as nitroglycerin.

The presence of glycerol makes saponification economically valuable, since both soap and glycerol are useful products. Historically, soap-making was one of the earliest large-scale chemical industries, and glycerol recovery became an important by-product process.

Thus, the correct answer is Glycerol, which is produced alongside soap in the saponification of triglycerides.