Soap is sodium or potassium salt of

Stearic acid

Oleic acid

Palmitic acid

All of the above

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC NDA-1 – 2016

Download PDF Attempt Online

Soaps are traditionally made by the saponification of fats or oils with a strong alkali, such as sodium hydroxide (for hard soap) or potassium hydroxide (for liquid soap). Fats and oils are triglycerides, which are esters formed from glycerol and fatty acids. Saponification breaks down the triglyceride into glycerol and the sodium or potassium salts of the fatty acids.
Common fatty acids found in fats and oils used for soap making include saturated fatty acids like stearic acid (C₁₇H₃₅COOH) and palmitic acid (C₁₅H₃₁COOH), and unsaturated fatty acids like oleic acid (C₁₇H₃₃COOH). Therefore, soap is the sodium or potassium salt of long-chain fatty acids like stearic acid, oleic acid, and palmitic acid.

Soaps are salts of fatty acids. Saponification involves reacting fats/oils (triglycerides of fatty acids) with a strong base (NaOH or KOH) to produce soap (fatty acid salt) and glycerol.

The general formula for a soap molecule is R-COONa (sodium soap) or R-COOK (potassium soap), where R is a long hydrocarbon chain derived from a fatty acid. The long hydrocarbon chain is nonpolar and hydrophobic (water-repelling), while the carboxylate head (-COO⁻Na⁺ or -COO⁻K⁺) is polar and hydrophilic (water-attracting). This dual nature allows soap to emulsify grease and dirt in water.

Join Our Telegram Channel

More similar MCQ questions for Exam preparation:-