In a compartment model (in which two chambers are separated by a selectively permeable membrane), equal amounts of KA (organic anion) and NaCl are added to opposite sides. Assume that K+ and Cl- are permeant, and Na+ and A- are not.

 

At steady state, what would the relative distributions of ions be? Would there be a voltage difference between the compartments, and if so, which side would be negative? Would the osmotic pressure (number of solute particles per unit volume) be relatively balanced?

Is this a homework question?

Is this a homework question?

 

This is an exam revision question. My assumption is that the chemical gradient would send the two permeable ions across the membrane until they reach equilibrium and there would be no net charge because that would also reach equilibrium. But I'm probably wrong. I don't know.