https://doi.org/10.1351/goldbook.S06024

The practical activity coefficient of electrolyte B is given by \[\gamma _{\pm }=\frac{a_{\pm }}{\sqrt{\nu _{\text{+}}^{\nu _{\text{+}}}\ \nu _{\text{-}}^{\nu _{\text{-}}}}\ \frac{m_{\text{B}}}{m^{\text{+}}}}\] where a± is the mean activity of B in solution, m B is the molality of B, m + = 1 mol kg-1, ν + is the number of cations and ν- the number of anions in the chosen group B which is taken as the electrolyte. \[\nu = \nu _{\text{+}}+\nu _{\text{-}}\]*Source: *

PAC, 1974,*37*, 499. 'Electrochemical nomenclature' on page 510 (https://doi.org/10.1351/pac197437040499)

PAC, 1974,