What is the acid-base properties of water?

The acid-base properties of water:

Water, as we know, is a unique solvent. One of its special properties is its ability to act either as an acid or as a base. Water functions as a base in reactions with acids such as HCl and CH₃COOH, and it functions as an acid in reactions with bases such as NH₃. Water is a very weak electrolyte and therefore a poor conductor of electricity, but it does undergo ionization to a small extent:

This reaction is sometimes called the autoionization of water. To describe the acid-base properties of water in the Brønsted framework, we express its autoionization as follows:

The acid-base conjugate pairs are (1) H₂O (acid) and OH^- (base) and (2) H₃O⁺ (acid) and H₂O (base).