How do you calculate buffer capacity?

1 Answer
Dec 7, 2014

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# 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 : (From Wiki)

#C_A# is the concentration of the acid.