Concept:The reactivity of alcohols towards substitution depends heavily on the stability of the intermediate carbocation formed during the reaction.
Solution:- The Lucas test uses a reagent consisting of concentrated \( HCl \) and anhydrous Zinc Chloride (\( ZnCl_2 \)).
- It differentiates alcohols based on the time it takes for an insoluble alkyl chloride layer (cloudiness/turbidity) to form.
- Tertiary alcohols: Form turbidity immediately (highly stable carbocation).
- Secondary alcohols: Form turbidity in 5-10 minutes.
- Primary alcohols: Do not form turbidity at room temperature.
Why other options are incorrect:Benedict's reagent is used for aldehydes. Grignard reagents are used for synthesis, not primarily as qualitative discrimination tests. Bloor's reagent is used for lipid extraction, unrelated to alcohol classification.
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