The buffering capacity of a buffer is maximum at pH equal to
The pH of a buffer is determined by the Henderson-Hasselbalch equation So, at the max buffering capacity, = . This is because a buffer reacts in the following manner--it is able to buffer against equal amounts of acid (H+) or base (OH-) added. A- + H+ - HA HA + OH- - H2O + A- Finally, we can see from the above Henderson-Hasselbalch equation that when = , pH = pKa.
0.5 pKa
pKa
pKa+1
2pKa
Enzymes