Chapter 19.7, Problem 17P

Interpretation Introduction

Interpretation:

The reason should be given for ${\text{pK}}_{\text{a}}$ of Imidazole is $14.5$ and pyrrole is $\text{pKa}17$.

Concept Introduction:

Imidazole is the aromatic compound and also the heterocyclic ring of histidine. It exists in both protonated and unprotonated form at $\text{pH}=7.4$.

Pyrroles are the five membered rings containing nitrogen atom and the pi cloud contains three pairs of pi electrons.