Chapter 8, Problem 1Q

Interpretation Introduction

Interpretation:

The purposeof the use of concentrated ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ in the first step of the preparation of aspirinneeds to be identified.

Concept Introduction:

The preparation of aspirin takes place by the reaction of salicylic acid and acetic anhydride represented as follows:

  

The -OH group of the salicylic acid reacts with acetic anhydride to form ester thus, the formation of aspirin is an esterification reaction.

Answer to Problem 1Q

To activate the reaction.

Explanation of Solution

The acid serves to protonate one double bonded oxygen on the acetic anhydride this makes the reaction with the salicylic acid faster.

The mechanism is represented as follows:

  

Thus, the acid acts as the catalyst during the esterification reaction by making the carbonyl group of anhydrous acetic acid more reactive.

Conclusion

Thus, the purpose of the use of concentrated ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ in the first step of the preparation of acetylsalicylic acid is to activate the reaction by making anhydrous acetic acid more reactive.