Single Choice

(I)$$ CH_3CH_2CH_2OH $$ (ii) $$ CH_3-CHOH-CH_3$$ (iii) $$ CH_3-C(CH_3)(OH)CH_3$$ were treated with Lucas reagent (conc. $$ HCl +ZnCl_2 ) $$. What results do you expect at room temperature?

A(ii) and (iii) react immediately and (i) in about 5 minutes
B(iii) reacts immediately, (ii) reacts in about 5 minutes and (i) not at all
Correct Answer
C(i) reacts immediately, (ii) reacts in about 5 minutes and (iii) not at all
D(i) reacts in about 5 minutes, (ii) reacts in about 15 minutes and (iii) not at all

Solution

Tertiary alcohols react immediately with Lucas reagent as evidenced by turbidity owing to the low solubility of the organic chloride in the aqueous mixture.
Secondary alcohols react within five or so minutes (depending on their solubility).
Primary alcohols do not react appreciably with Lucas reagent at room temperature.

$$I$$ is a primary alcohol, $$II$$ is secondary alcohol and $$III$$ is a tertiary alcohol.

Hence, option $$B$$ will be correct.

SIMILAR QUESTIONS

Alcohols, Phenols and Ethers

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?

Alcohols, Phenols and Ethers

From amongst the following alcohols the one that would react fastest with conc. $$HCl$$ and anhydrous $${Z}n{C}l_{2}$$, is:

Alcohols, Phenols and Ethers

An alcohol gave Lucas test in about 5 minutes. When the alcohol was treated with hot concentrated $$H_2SO_4$$, it gave an alkene of molecular formula $$C_4H_8$$ which on ozonolysis gives single product with molecular formula $$C_2H_4O$$. The structure of alcohol is:

Alcohols, Phenols and Ethers

Lucas test is given by an alcohol within 5 minutes. 0.22 g of which liberates 56 mL of $$ CH_4$$ at STP on treating with $$CH_3MgI$$.The structure of alcohol is:

Alcohols, Phenols and Ethers

Which of the following compounds reacts immediately with Lucas reagent?

Alcohols, Phenols and Ethers

Which alcohol will give immediate turbidity on shaking with HCl at room temperature?

Alcohols, Phenols and Ethers

An alcohol (A) gives Lucas test within 5 min. 7.4 g of alcohol when treated with sodium metal liberates 1120 mL of $$H_2$$ at STP. What will be alcohol (A)?

Alcohols, Phenols and Ethers

Which of the following alcohols reacts most readily with Lucas reagent?

Alcohols, Phenols and Ethers

Vinyl chloride and ethyl chloride can be distinguished by:

Alcohols, Phenols and Ethers

Which of the following will react fastest with Lucas reagent?

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