UPSC NDA I 2016 General Ability Solved Paper

Concept:Soap is the sodium or potassium salt of a mixture of fatty acids obtained from natural oils and fats.Explanation:Soap is produced by the saponification reaction where triglycerides (oils or fats) are heated with a strong base like $\mathrm{NaOH}$ (making hard soap) or $\mathrm{KOH}$ (making soft soap).The reaction breaks the triglyceride into glycerol and the sodium or potassium salts of the constituent fatty acids.Common fatty acids found in these mixtures include stearic acid ($\mathrm{C}_{17}\mathrm{H}_{35}\mathrm{COOH}$), oleic acid ($\mathrm{C}_{17}\mathrm{H}_{33}\mathrm{COOH}$), and palmitic acid ($\mathrm{C}_{15}\mathrm{H}_{31}\mathrm{COOH}$), along with others like myristic and lauric acids.Each of these fatty acid salts contributes to the lathering, cleaning, and washing properties of soap.Therefore, soap is not exclusively the salt of a single fatty acid but a blend of many, including all the options listed.Answer:D. All of the above