Question

7) Which of the following is obtained as a byproduct in the manufacture of soap.

• A. glycerine
• B. sodium hydroxide
• C. vegetable oil
• D. Salt of fatty acids

Answer 1

The correct option is A

glycerine

Explanation for the correct option:

(A) Soap is formed by the process known as saponification. When triglycerides react with potassium hydroxide (KOH) or sodium hydroxide (NaOH) it leads to formation of sodium or potassium salts of fatty acids and gycerol. The glycerol obtained in the reaction is a byproduct obtained with soap.

$\mathrm{Triglycerides}+\mathrm{Sodium}\mathrm{or}\mathrm{Potassium}\mathrm{Hydroxide}\to \mathrm{Soaps}+\mathrm{Glycerol}$

Explanation for the incorrect options:

(B) Sodium hydroxide is used as reactant in the saponification process.

(C) Vegetable oil is used as reactants in the saponification process.

(D) Salt of fatty acids (sodium or potassium) is obtained as the main product of the reaction which is soap.

Hence, the correct option is (A).