Question

Given below are two statements:
Statement I: In Lucas test, primary, secondary and tertiary alcohols are distinguished on the basis of their reactivity with conc. HCl +ZnCl₂, knowns as Lucas Reagent.
Statement II: Primary alcohols are most reactive and immediately produce turbidity at room temperature on reaction with Lucas Reagent.
In the light of the above statements, choose the most appropriate answer from the options given below:

• A. Both statement I and Statement II are correct
• B. Both statement I and Statement II are incorrect
• C. Statement I is correct but Statement II is incorrect
• D. Statement I is incorrect but statement II is correct

Answer 1

The Correct Option is C

In this problem, we need to evaluate the correctness of the two given statements related to the Lucas test in chemistry.

Statement I: In Lucas test, primary, secondary, and tertiary alcohols are distinguished on the basis of their reactivity with conc. HCl + ZnCl₂, known as Lucas Reagent.

Statement II: Primary alcohols are most reactive and immediately produce turbidity at room temperature on reaction with Lucas Reagent.

Let's analyze each statement:

Statement I Analysis:
The Lucas test is used to classify alcohols of low molecular weight. It is based on their reactivity with Lucas reagent (conc. HCl + ZnCl₂). The test distinguishes alcohols by the time taken to produce turbidity due to the formation of the corresponding alkyl chloride. Tertiary alcohols react immediately, secondary alcohols react within five minutes, and primary alcohols do not react appreciably at room temperature.
Conclusion: Statement I is correct.

Statement II Analysis:
According to the Lucas test, tertiary alcohols react the fastest, followed by secondary alcohols. Primary alcohols are the least reactive and usually do not form turbidity without heating. Therefore, the assertion that primary alcohols react most readily and immediately produce turbidity is incorrect.
Conclusion: Statement II is incorrect.

Final Answer: Statement I is correct but Statement II is incorrect.