Multivalent-electrolyte screening-length ratio
= Multivalent-electrolyte screening-length ratio
{title2=$\lambda_{D,2}/\lambda_{D,1}=\sqrt{I_1/I_2}$}
For fully dissociated <electrolytes> at the same <temperature> and <solvent> <permittivity>, linear screening theory gives $\lambda_D^{-2}\propto\sum_i c_i z_i^2=2I$. A divalent symmetric salt of formula <concentration> $c$ has $I=4c$, not $c$ or $2c$. <ion> association and nonideal concentrated-solution effects limit this comparison.