A mixture consisting of 1-butanol, 2-butanol, 2-methyl-2-propanol, benzyl alcohol, and allyl alcohol — Haloalkanes and Haloarenes Chemistry Question

💡 Solution & Explanation

The Lucas test distinguishes alcohols based on the stability of the intermediate carbocation formed via the $S_N1$ mechanism. The rate of reaction dictates the appearance of turbidity (insoluble alkyl chloride). 1. 1-butanol ($1^\circ$) forms a highly unstable primary carbocation; yields no turbidity at room temperature. 2. 2-butanol ($2^\circ$) forms a secondary carbocation; gives turbidity in about 5 minutes. 3. 2-methyl-2-propanol ($3^\circ$) forms a stable tertiary carbocation; gives immediate turbidity. 4. Benzyl alcohol forms a resonance-stabilized benzylic carbocation; gives immediate turbidity. 5. Allyl alcohol forms a resonance-stabilized allylic carbocation; gives immediate turbidity. Thus, 3 alcohols react immediately.