What occurs during the saponification of a triglyceride fat using aqueous potassium hydroxide (KOH)?
Answer and explanation
Correct answer: B. Base-catalyzed ester hydrolysis producing glycerol and potassium salts of fatty acids (soap)
- Step 1: Triglycerides are triesters formed from glycerol and three fatty acid chains.
- Step 2: Treatment with strong alkali (KOH or NaOH) cleaves the ester linkages via nucleophilic acyl substitution.
- Step 3: The products are glycerol (propane-1,2,3-triol) and potassium carboxylates, known as soft soaps.
Answer
Base-catalyzed ester hydrolysis producing glycerol and potassium salts of fatty acids (soap).
Why not the others: 'Acid-catalyzed condensation producing high-molecular-weight polyesters' describes polymer synthesis; 'Catalytic hydrogenation converting unsaturated oils to solid saturated fats' describes hardening of vegetable oils using H2 and nickel; 'Electrophilic substitution across the glycerol hydrocarbon backbone' is chemically incorrect for esters.
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