Debye Hückel Activity Coefficient: Activity coefficient of an ion in a dilute solution

I = Ionic Strength ; z =  Charge number of  an ionic specie ; f = Activity coefficient ;

A= A  constant that depends on temperature.
(A is assumed to be 0.509 mol^-1/2 kg-1/2 which corresponds to water at 25^oC)

Activity coefficient of an ionic specie is related to it's ionic strength. You may use our ionic strength calculator: visit. It is to be kept in mind that the calculated f corresponds to it's activity coefficient in water at 25^oC, since A is assumed to be 0.509 mol^-1/2 kg^-1/2. A is dependent on temperature and solvent.