A weak acid $($HA$)$ has the dissociation constant $K_a$ for $HA{H}^{+}+A^{-}.$ The variations of quotient $([H^{+}]\frac{A}{HA})$ with the ionic strength $($I$)$ of the solution are obtained as following.

$\backslash$table$[[[$:$[H^{+}]\frac{A^{-}}{H}A\},$I