I'm kind of curious as to the relationship between resistance and the yield of electrochemical methods. If I have my electrodes rather close together in a conductive solution the resistance will be smaller than if I had them further apart and more current can flow. Would there be any penalty for having the electrodes close together like this? Will I miss some ions in solution, or are they distributed equally in solution and so will always move towards the electrodes as some will be taken out of the solution as gases (such as electrolysis of (H2O -> 2H2 + O2))?
It really depends on the process and how homogeneous electric filed is needed. The more are electrodes close together, the inhomogeneity will be greater.
The second problem will be with the homogenity of the solution. You can assume, that electrolyte is kinda homogeneous in a bulk. But more close you get to the electrode, the more is the electrolyte separated.
Ions, as a charged particles, are transferred to near electrode surface.