The effect of strong base on water is to dramatically increase the concentration of
Water always contains at least small concentrations of both
At equilibrium, which is attained quickly for this reaction at room temperature, the product of
Pure water contains equal concentrations of the two ions, so at neutral pH conditions (pH=7),
Addition of strong base (e.g., NaOH) releases hydroxide ions directly into solution because NaOH dissolves completely as
The pH of this solution is 12.
A buffer solution consists of moderately high concentrations of an acid and its conjugate base. An example is a solution containing 0.1M carbonic acid
Addition of strong base to this buffer has the effect of reacting with some of the buffer acid
In the same way, addition of small amounts of strong acid to a buffer solution will react with the buffer base and convert it to acid, leaving the pH nearly unchanged.
Blood contains many different buffer acid/base combinations, but the most important one is carbonic acid / bicarbonate ion, which keeps the pH of blood nearly constant at about 7.35.