Chapter 21, Problem 1Q

Interpretation Introduction

Interpretation:

The formulas of the salts that may precipitate when the reaction mixture is cooled during the formation of n-butyl bromide from n-butyl alcohol and $\text{HBr}$ needs to be determined.

Concept Introduction:

During the formation of n-butyl bromide from n -butyl alcohol and $\text{HBr}$, some salt is precipitated.

Answer to Problem 1Q

When the reaction mixture is cooled during the formation of n-butyl bromide from n-butyl alcohol and $\text{HBr}$, ${\text{NaHSO}}_{\text{4}}$ may precipitate.

Explanation of Solution

The formation ofn -butyl bromide is formed by the reaction of n -butylalcohol with $\text{HBr}$. The reaction follows the bi-molecular nucleophilic substitution reaction as the transition state is formed as an intermediate.

Here, $\text{HBr}$ is formed by the reaction of $\text{NaBr}$ with H₂SO₄. Hence the reaction can be written as:

  ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{OH + NaBr +H}}_{\text{2}}{\text{SO}}_{\text{4}}\stackrel{}{\to }{\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{Br +NaHSO}}_{\text{4}}{\text{ +H}}_{\text{2}}\text{O }$

When the reaction mixture is cooled during the formation of n-butyl bromide from n-butyl alcohol and $\text{HBr}$, ${\text{NaHSO}}_{\text{4}}$ may precipitate.

Conclusion

When the reaction mixture is cooled during the formation of n-butyl bromide from n-butyl alcohol and $\text{HBr}$, ${\text{NaHSO}}_{\text{4}}$ may precipitate.