How Does a Buffer Solution Work?
Buffer Solution Theory Buffer solutions consist of an equilibrium between a weak acid and the acid’s conjugate base. As a result, on one side of the reaction there is water and the weak acid, and on the other side there are hydrogen ions and the conjugate base. Because this system is at an equilibrium, addition of hydrogen ions (acid) will cause the equilibrium to shift to favor the formation of the weak acid. Conversely, addition of hydroxide (a base that will neutralize hydrogen ions) will cause the equilibrium to favor the production of additional hydrogen ions. The fact that there is an equilibrium that responds to changing concentrations of hydrogen ions in effect mitigates and minimizes the effects of adding or taking away hydrogen ions. Thus, buffers are useful for keeping a solution within a certain pH range. Unbuffered solutions can have their pH levels swing wildly with the addition or subtraction of small amounts of hydrogen ion; the presence of a buffer stabilizes the pH. B
