How do you calculate buffer capacity?

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Answer 1 · 2014-12-07T00:06:05

A buffer solution will maintain a constant pH with the addition of small amounts of acid and alkali.

There is a limit to the amount of acid or alkali that the buffer can handle.

The buffer capacity is given by the expression:

#(dn)/(d(pH))#

#dn# is a tiny amount of added base which results in tiny change in pH shown as #d(pH)#

If you have a weak acid whose dissociation constant is #K_a# then the buffer capacity is given by :

$upload.wikimedia.org$ (From Wiki)

#C_A# is the concentration of the acid.