Question

Which one is the correct order of
reactivity of different types of alcohol
towards hydrogen halide?
O 1° alcohol > 2° alcohol > 3 alcohol
02 alcohol > 1' alcohol > 3 alcohol
O 3 alcohol > 1° alcohol > 2° alcohol
O 2
3° alcohol > 2º alcohol > 1° alcohol
.​

Answer 1

3° alcohol > 2º alcohol > 1° alcohol

• When alcohols react with the hydrogen halide, substitution takes place producing the alkyl halide & water.

• The order of reactivity of alcohols : 3° > 2° > 1° methyl.

• The order of the reactivity of hydrogen halides is HI > HBr > HCl.

• The reaction is a acid catalyzed. Alcohols react with  strongly acidic hydrogen halides HCl, HBr, & HI, but they don't react with  the nonacidic NaCl, NaBr, or the NacI. Primary & secondary alcohols can be converted to the alkyl chlorides & bromides by allowing them to react with the mixture of sodium halide & sulfuric acid.

• The carbocation re-arrangements is the extremely common in the organic chemistry reactions are defined as movement of the carbocation from a unstable state to the more stable state through the use of various structural reorganizational "shifts" within  molecule. Once  carbocation has shifted over to  different carbon, we can say that there is the structural isomer of  initial molecule. However, then phenomenon is not as the simple as it sounds.

• The most common methods for the converting 1º- and 2º-alcohols to  corresponding chloro & bromo alkanes (that is replacement of  hydroxyl group) are the treatments with a thionyl chloride & phosphorus tribromide, respectively.

Hence,

The answer is  3° alcohol > 2º alcohol > 1° alcohol .

#SPJ3