Question

Explain why the free fatty acids derived from some soaps solidify, while others remain liquid. Give examples

Answer 1

Undaturated fatty acids(containing double and triple bonds between C-atoms) are unable to pack properly due to kinks in them and due to cis/trans - structure. Hence they remain as liquid at room temperature. e.g Oleic acid ( a cis-unsaturated fatty acid), Linoleic Acid etc

However saturated fatty acids( do not contain any double or triple bond) are well packed due to absence of cis/trans - structure. Hence they remain solid at room temperature. e.g palmitic acid, lauric acid etc.