Question

Explain how a buffer works to keep the pH of a solution relatively constant.

Answer 1

A buffer solution contains a conjugated base and a conjugated acid both in significant amount. When we add acid to a buffer solution the conjugated base will neutralize all the H+ introduced by the acid. This makes that the [H+] present on the buffer solution doesn´t change. Now, if we add base to the buffer solution, the conjugated acid will neutralize all the OH- ions and the amount of OH- in the solution will no change. That is why the pH is relatively constant.

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