How do buffers resist pH change?

1 Answer
Oct 10, 2016

Well, they usually do so superbly, depending on the capacity of the buffer.

Explanation:

The defining equation is:

#pH=pK_a+log_10{[[A^-]]/[[HA]]}#

And thus an equimolar solution of a weak acid and its conjugate base will maintain a #pH# close to the #pK_a# of the acid should small quantities of acids or bases be added. Biological systems are extensively buffered.

See here for its derivation.