Editing Imidazole (section)

===Amphoterism===
Imidazole is [[amphoteric]], which is to say that it can function both as an acid and as a base. As an acid, the [[Dissociation constant#Acid–base reactions|p''K''<sub>a</sub>]] of imidazole is 14.5, making it less acidic than carboxylic acids, phenols, and imides, but slightly more acidic than alcohols. The acidic proton is the one bound to nitrogen. Deprotonation gives the imidazolide anion, which is symmetrical. As a base, the p''K''<sub>a</sub> of the conjugate acid (cited as p''K''<sub>BH<sup>+</sup></sub> to avoid confusion between the two) is approximately 7, making imidazole approximately sixty times more basic than [[pyridine]]. The basic site is the nitrogen with the lone pair (and not bound to hydrogen). Protonation gives the imidazolium cation, which is symmetrical.