Lec -12-

Left to right, the anions transport 2F of electricity from right to left
1- Consequently, 2 equivalents of cations must move from the anode compartment into the center, and the same number of equivalents from the center into the cathode
2- Simultaneously, 2 equivalents of anions must move past these planes from the cathode compartment to the center, and also 2 of these from the center into the anode compartment.
from III it is evident that the concentration in the central compartment has not been affected by the passage of current. And, the concentrations in the cathode and anode compartments have both decreased 2 equivalents.
"when the speeds of the ions are not the same"
I- When the speed of the cation is 3 times that of anion

II- But, since the cation carries 3 times as much current as the anion, 3 equivalents of positive ions must migrate from anode to center, and from center to cathode compartment.
III- At the same time only 1 equivalent of anions leaves the cathode section, and only 1 equivalent leaves the center for anode compartment.