JEE Advanced levelSingle correct optionDifficulty 3 of 3el194
Dodecan-1-ol is treated with conc. HX2SOX4 and the product is neutralised with NaOH to give a surfactant Z. Which description of Z is correct according to the standard NCERT treatment?
AAnionic detergent with a linear chain, biodegradable and forming no scum in hard water
BCationic detergent with germicidal action, forming scum in hard water
CA soap, since it is the sodium salt of a fatty acid
DNon-ionic detergent containing an ester linkage
Answer: A
The product is CX12HX25OSOX3Na, sodium lauryl sulphate: a sulphate ester salt, so it is anionic and not a carboxylate soap. Its unbranched chain makes it biodegradable, and it does not give scum with CaX2+ or MgX2+ in hard water.