Water (as amphoteric)

Water is considered amphoteric because it can act as both an acid and a base, depending on the situation. This means it can donate a hydrogen ion (acting as an acid) or accept a hydrogen ion (acting as a base). For example, when water reacts with ammonia, it donates a hydrogen ion to become hydroxide, while with hydrochloric acid, it accepts a hydrogen ion, forming hydronium. This unique property allows water to participate in a wide range of chemical reactions, making it essential for processes like biological functions and chemical manufacturing.