Compartments A and B are separated by a membrane that is permeable to K+ but not to Cl-.At time zero,a solution of KCl is poured into compartment A and pure H2O is poured into compartment B.Now they are emptied and the membrane replaced with one that is permeable to both K+ and Cl-,but no other ions.At time zero,a solution of NaCl is poured into compartment A and a solution of KA (A is an anion other than Cl-)is poured into compartment B.At equilibrium,
A)Compartment A will be negatively charged relative to B
B)There is a net flux of K+ from B to A
C)There is a concentration gradient favoring Cl- diffusion from A to B and this gradient is balanced by an electric force favoring diffusion from B to A
D)Both there is a net flux of K+ from B to A and there is a concentration gradient favoring Cl- diffusion from A to B and this gradient is balanced by an electric force favoring diffusion from B to A are correct
E)All of the choices are correct

Question

Quizplus · Accepted Answer

Permeability of the membrane to both K+ and Cl- means that both ions can diffuse between compartments A and B. At equilibrium, the concentration gradient for Cl- diffusion from compartment A to B will be balanced by an opposing electric force favoring diffusion from B to A, as compartment A will have a net negative charge relative to B due to the presence of K+ ions that are trapped in compartment A. Therefore, there is no net flux of Cl- ions. However, K+ ions will diffuse from compartment B to A down their concentration gradient, which means there is a net flux of K+ ions from B to A. Thus, choice D is correct.

Compartments a and B Are Separated by a Membrane That