See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Enol Content of Ethyl Acetate **Understanding Enol Formation:** Ethyl acetate ($CH_3COOC_2H_5$) exists in equilibrium with its enol tautomer: $$CH_3COOC_2H_5 \rightleftharpoons CH_2=C(OH)OC_2H_5$$ The enol form is stabilized by solvation. Maximum enol content occurs in the solvent that **least stabilizes the keto form** (carbonyl). **Analyzing each solvent:** - **(A) $H_2O$:** Highly polar solvent with strong hydrogen bonding. Strongly stabilizes the polar keto carbonyl → **minimum enol content** - **(B) $CH_3COOH$:** Carboxylic acid is polar and forms hydrogen bonds with the $C=O$ group → **stabilizes keto form** → low enol content - **(D) Aqueous HCl:** Acidic aqueous solution; strong hydrogen bonding with carbonyl → **stabilizes keto form** → low enol content - **(C) n-hexane:** Non-polar, non-protic solvent with **no hydrogen bonding capability**. Cannot stabilize the keto carbonyl, so the equilibrium shifts toward the enol tautomer → **maximum enol content** **Answer: (C) n-hexane** provides minimal solvation of the polar keto form, allowing the equilibrium to shift maximally toward the enol tautomer.