Which of the following statements about soaps is correct?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Soaps are sodium or potassium salts of long-chain carboxylic acids.
Soap is made by heating an oil or fat with sodium hydroxide or potassium hydroxide (saponification). The product is the sodium or potassium salt of a long-chain fatty acid, that is, a long-chain carboxylic acid such as stearic acid; sodium stearate is a common soap.
Why the other options are incorrect
Option (2) Soaps are sodium or potassium salts of long-chain aldehydes. — Incorrect. Aldehydes (–CHO group) are not acids, so they do not form sodium or potassium salts.
Option (3) Soaps are sodium or potassium salts of long-chain amines. — Incorrect. Amines (–NH2 group) are basic compounds and do not form salts with sodium or potassium.
Option (4) Soaps are sodium or potassium salts of long-chain ketones. — Incorrect. Ketones (C=O group inside the chain) are not acids and form no such salts.