For 10 points, name this doubly eponymous equation for calculating activity coefficients.
This equation was motivated by noting that a correction needed to be made to an equation given by Guldberg and Waage, and it was modified to consider association between oppositely charged ions by Niels Bjerrum. One alternative to this equation includes a sum over parameters that are derived from experimental calculations of the osmotic coefficient and is used for higher molarities; that is the Pitzer equation. It states that the natural log of gamma is proportional to the square of the charge number of the species and the square root of the ionic strength of the solution. One of its namesakes names a rule for aromaticity and the other names a unit of electric dipole moment. For 10 points, name this doubly eponymous equation for calculating activity coefficients.
This equation was motivated by noting that a correction needed to be made to an equation given by Guldberg and Waage, and it was modified to consider association between oppositely charged ions by Niels Bjerrum.
DebyeHuckel equation or theory