NEETChemistryAlcohols Phenols and Ethers
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): tert-Butyl alcohol produces turbidity immediately with Lucas reagent at room temperature, whereas n-butyl alcohol does not. Reason (R): Primary alcohols undergo S _ N 2 reactions faster than tertiary alcohols. In the light of the above statements, choose the most appropriate answer from the options
Options
- ABoth Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation for Assertion (A).
- BBoth Assertion (A) and Reason (R) are correct but Reason (R) is not the correct explanation for Assertion (A).
- CAssertion (A) is correct but Reason (R) is incorrect.
- DAssertion (A) is incorrect but Reason (R) is correct.
Correct answer
B. Both Assertion (A) and Reason (R) are correct but Reason (R) is not the correct explanation for Assertion (A).
Step-by-step solution
Assertion (A) is correct: Lucas reagent is a mixture of concentrated HCl and anhydrous ZnCl ₂ . Tertiary alcohols like tert-butyl alcohol react immediately to produce turbidity (due to the formation of an insoluble alkyl chloride), while primary alcohols like n-butyl alcohol do not produce turbidity at room temperature. Reason (R) is correct: In general, primary substrates undergo S _ N 2 reactions faster than tertiary substrates due to less steric hindrance. However, Reason (R) is not the correct explanation for A