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Question
Consider the following comments about saponification reactions:
I. Heat is evolved in these reactions.
II. For quick precipitation of soap, sodium chloride is added to the reaction mixtures.
III. Saponification reactions are a special kind of neutralisation reactions.
IV. Soaps are basic salts of long-chain fatty acids.
The correct comments are
(a) I, II and III
(b) II, III and IV
(c) I, II and IV
(d) Only I and IV
Solution
Soaps are sodium or potassium salts of long-chain fatty acids. Since sodium and potassium hydroxides are bases, their solutions in water are alkaline.
Dissolution of sodium or potassium hydroxide in water evolves a large amount of heat. Thus, saponification reactions are exothermic in nature.
Common salt is added in a saponification reaction, as it helps in the precipitation of a soap by decreasing the solubility of the soap.
Thus, statements I, II and IV are correct.
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