WATER:

We typically talk about acid-base reactions in
aqueous-phase environments -- that is, in the presence of water.
The most fundamental acid-base reaction is the dissociation of water.



In this reaction, water breaks apart to form a hydrogen
ion and a hydroxide ion In pure water,
we can define a special equilibrium
constant (Kw) as follows:



Where Kw is the equilibrium constant for water at 25° C (unitless)
is the molar concentration of hydrogen

is the molar concentration of hydroxide

An equilibrium constant less than one (1) suggests that the reaction
prefers to stay on the side of the reactants -- in this case, water likes
to stay as water. Because water hardly ionizes, it is a very poor conductor of electricity.