Single Choice

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

A2-butanol
B2-methyl propan-2-ol
Correct Answer
C2-methylpropanol
D1-butanol

Solution

The reagent, conc. $$HCl$$ and anhydrous $$ZnCl_2$$ is Lucas reagent, which is used to distinguish between $$1^0,\ 2^0\ and\ 3^0\ $$ alcohols.

$$3^0$$ alcohol + Lucas reagent → Immediate turbidity.

$$2^0$$ alcohol + Lucas reagent → Turbidity after 5 mins.

$$1^0$$ alcohol + Lucas reagent → No reaction.

$$CH_3C(CH_3)OH-CH_3$$ is tertiary alcohol reacts fastest with Lucas reagent.

Therefore, option B is 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

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?

Alcohols, Phenols and Ethers

Explain the following behavior: Reactivity of all the three classes of alcohols with conc. HCl and $$ZnCl_2$$ is different.

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