One improvement on this equation adds a term containing a coefficient of negative 0.3, while most improvements of this equation inserts an I sub c to the one-half power term to both its numerator and denominator. For an aqueous solution, this equation reduces to having a proportionality constant of 1.173. The primitive model's resultant Mean Spherical Approximation is an improvement on this equation and reduces to it at the low-coupling Mayer limit. This equation models point charges in a medium with a constant permeability, and improvements to this equation include ones named for Guntelberg, Davies, (*) and Pitzer. This equation states that the natural logarithm of 
One improvement on this equation adds a term containing a coefficient of negative 0.3, while most improvements of this equation inserts an I sub c to the one-half power term to both its numerator and denominator. For an aqueous solution, this equation reduces to having a proportionality constant of 1.173. The primitive model's resultant Mean Spherical Approximation is an improvement on this equation and reduces to it at the low-coupling Mayer limit. This equation models point charges in a medium with a constant permeability, and improvements to this equation include ones named for Guntelberg, Davies, (*) and Pitzer. This equation states that the natural logarithm of gamma is proportional to kappa divided by 8 pi times the product of permeabilities and Boltzmann's constant. This equation only applies to strong electrolytes in dilute solutions. For 10 points, name this equation that is used to find activity coefficients of ionic solutions.
One improvement on this equation adds a term containing a coefficient of negative 0.3, while most improvements of this equation inserts an I sub c to the one-half power term to both its numerator and denominator.
Debye-Huckel equation