Reversible molecular
reactions involving weak binding interactions between two molecules, or a molecule and an ion, effectively behave just like weak acids or bases, which act as pH buffers. Thus, the
quantitative and graphical aspects of simple and complex pH buffers will be developed, starting here with acetic acid, a monoprotic buffer representing the simplest of buffer systems.
Buffers act like sponges,
soaking up or releasing protons.
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- Buffers effectively "control" the pH or free H+
ion concentration, [H+], in a solution by adsorbing or releasing weakly bound H+
either as the free acid (H+ ion) is added to the system or free H+
ion is removed from the system by the addition of base or free hydroxyl ion, OH-.
- For weak dissociation/association reactions, the
concentrations of products and reactants at equilibrium are all related
to each other by a fixed constant called an equilibrium constant.
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