1. Tardigrade
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  3. Chemistry
  4. An unknown alcohol is treated with the Lucas reagent to determine whether the alcohol is primary, secondary or tertiary. Which alcohol reacts fastest and by what mechanism?

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Q. An unknown alcohol is treated with the Lucas reagent to determine whether the alcohol is primary, secondary or tertiary. Which alcohol reacts fastest and by what mechanism?

UP CPMTUP CPMT 2015Alcohols Phenols and Ethers

Solution:

The reaction of alcohol with Lucas reagent is mostly an $S _{ N } 1$ reaction and the rate of reaction is directly proportional to the stability of carbocation formed in the reaction. Since $3^{\circ} R - OH$ forms $3^{\circ}$ carbocation (most stable), hence it will react fastest.