Ionization of WaterUsually pure water is considered to be a nonelectrolyte. Nevertheless, it actually can conduct small amounts of electricity. This is because of the self-ionization of water. Since the species that act as the acid and the base are one and the same, we can describe it as follows:
A proton is grabbed from one water molecule, and is accepted by another water molecule. The resulting products are hydronium and hydroxide ions.
The equilibrium expression (KW) is written as:
KWis more correctly called the ion-product constant for water, which is actually the equilibrium value of the ion product.