Single Choice

$$R-OH+HX\rightarrow R-X+H_{2}O$$. In the given reaction, the reactivity of different alcohols is:

A$$3^{o}> 2^{o}> 1^{o}$$
Correct Answer
B$$3^{o}< 2^{o}< 1^{o}$$
C$$3^{o}< 2^{o}> 1^{o}$$
D$$2^{o}< 1^{o}> 3^{o}$$

Solution

When treated with HBr or HCl alcohols typically undergo a nucleophilic substitution reaction to generate an alkyl halide and water. Alcohol relative reactivity order : $$3^o > 2^o > 1^o > \text{methyl}$$. Hydrogen halide reactivity order : $$HI > HBr > HCl > HF$$ (paralleling acidity order). Reaction usually proceeds via an SN1 mechanism which proceeds via a carbocation intermediate, that can also undergo rearrangement. Methanol and primary alcohols will proceed via an SN2 mechanism since these have highly unfavourable carbocations. Hence, the correct option is $$A$$

SIMILAR QUESTIONS

Haloalkanes and Haloarenes

How many monochloro products can be formed when n-butane is subjected to monochlorination?

Haloalkanes and Haloarenes

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For the reaction, $${ C }_{ 2 }{ H }_{ 5 }OH+HX\underrightarrow { \quad \quad Zn{ X }_{ 2 }\quad \quad } { C }_{ 2 }{ H }_{ 5 }X$$, the order of reactivity is:

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