Question

The saponification produces sodium lactate (and not lactic acid) as the final product. What organic product was formed after the solution was acidified with HCl?
b) (2 points) Why does saponification produce sodium lactate (and not lactic acid) as the final product? Hint: Examine the acid-base reaction step in the saponification mechanism. The pKa of lactic acid is 3.85 and the pKa of methanol is 16.

Answer 1

Saponification means hydrolysis of esters in alkali or basic medium. So when the ester or oil is saponified the product would be salt of corresponding acid.

(1) Herein the given example, the product was sodium lactate and after the solution was acidified with HCl the product formed would be lactic acid.

(2) Why does saponification produce sodium lactate (and not lactic acid) as the final product because during the saponification firstly carboxylic acid and sodium alkoxide were formed but the proton is shifted to alkoxide from carboxylic acid due to its low pKa value.