In this answer to a question about viscosity of water in the presence of solutes, the Falkenhagen relation is given:
$$\frac{\eta_s}{\eta_0}=1+A\sqrt{c}$$ where $\eta_s$ is the solution viscosity, $\eta_0$ the solvent viscosity, $A$ a constant that depends on the electrostatic forces on the ions, and $c$ the concentration of the solute.
Now, in what order of magnitude would I assume A? Can one make general statements which group of solutes will be around which order of magnitude, like "expect A to be around $10^{-8}$ for single atom salts and $10^{-5}$ for long chained organics" (numbers plucked out of thin air) or similiar?
p.s. The relation is quoted from a paywalled paper that I can't access.