Moderate

Identify the Lucas reagent among the following

Correct answer: A. Conc. HCl & Anhydrous ZnCl2

  • A. Conc. HCl & Anhydrous ZnCl2
  • B. Dil. HCl & hydrated ZnCl2
  • C. Conc. HNO3 & Anhydrous ZnCl2
  • D. Conc. HNO3 & Anhydrous MgCl2

Explanation

Lucas reagent is a mixture of concentrated HCl and anhydrous ZnCl2. ZnCl2 acts as a Lewis acid and helps convert the alcohol's -OH group into a better leaving group, while HCl supplies chloride ions to form the alkyl chloride. The likely mistake is choosing dilute HCl and hydrated ZnCl2, which do not provide the required concentrated, strongly dehydrating conditions.

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About Alcohols

Alcohols contain a hydroxyl group attached to a saturated carbon atom and are classified as primary, secondary or tertiary. Their nomenclature, hydrogen bonding, acidity, oxidation, dehydration, reaction with sodium and conversion to haloalkanes are covered, along with the distinction between alcohols and phenols, where the hydroxyl group is attached directly to an aromatic ring.

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