A buffer refers to something that acts to reduce the impact of one thing on another - little bit like a shock absorber. For example, buffer in the computer world are areas shared by hardware devices that operate at different speeds. In acid-base chemistry, a buffer acts to reduce the impact on pH of adding acid or base to a chemical system.
18.2.2 Solve problems involving the composition and pH of a specified buffer system
Factors that can influence buffers are Dilution and Temperature.
Dilution, Ka and Kb as equilibrium constants are not changed by dilution. Nor is the ratio of acid to salt concentration, as both components will be decreased by the same amount. Therefore, diluting a buffer does not change its pH.
Nonetheless, diluting a buffer does alter the amount of acid or base it can absorb without significant changes in pH - the so-called buffering capacity. This depends on the molar concentration of its components, so decrease as they are lowered by dilution.
Temperature affects the values of Ka and Kb. it accordingly affects the pH of the buffer. This is why a constant temperature should be maintained in all work involving buffers such as calibration of pH meters. Temperature fluctuations must also be minimized in many medical procedures such as blood transfusions, due to the effect on the buffers in the blood.
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