Example: Bicarbonate buffer
Case 1: Too much base (i.e., too many OH- ions)
Because the NaOH dissociates (dissolves) in water the same way NaCl does, it adds more OH- ions to the solution and the solution should become basic. However, the H2CO3 also dissociates and the ions reassociate.
Both of the molecules which are formed are neutral.
Case 2: Too much acid (i.e., too many H+ ions)
Because the HCl dissociates (dissolves) in water the same way NaCl does, it adds more H+ ions to the solution and the solution should become more acidic. However, the HNaCO3 also dissociates and the ions reassociate. All of the end products are neutral.
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