There is no rigorously correct way to fi nd the pH of the buffer because the activity coeffi cient for a single ion (gCl) cannot be mea-sured  because  ions  only  come  in  pairs  with  counterions. ...

There is no rigorously correct way to fi nd the pH of the buffer because the activity coeffi cient for a single ion (gCl) cannot be mea-sured  because  ions  only  come  in  pairs  with  counterions.  However,  the  extended  Debye-Hückel  equation  8-6  allows  us  to  estimate  the  single-ion activity coeffi cients