Talk:Electrode potential

Diagram for the three electrode setup

I may be mistaken, but shouldn't this diagram have some kind of salt bridge in the middle to prevent spontaneous reaction of ions in solution? This would cause no current to flow into the electrodes, though would result in dissolution of the anode and depletion of the ionic species.Darkwraith (talk) 00:18, 2 August 2010 (UTC)

Generally not that I can see. Compare with diagrams: this this this and many other. Cheers. Stan J. Klimas (talk) 03:11, 2 August 2010 (UTC)

Deletion

Deleted this from the origin section for incoherence:

Electrode potential does not depend on the species in the reaction. Therefore the electrode potential for a half reaction of 2Cu2+(aq)+4e- -----> 2Cu(s) has the same electrode potential as Cu2+ (aq) +2e- -----> Cu (s) <<Electrochemistry Ch 19. Ebbing, Darrell; Gammon, Steven D.>>

Clarify IUPAC charge flow wrt. the sign of cell potential

Under

Potential difference of a cell assembled of two electrodes

there is the following statement:

When ΔV_cell is positive, then positive electrical charge flows through the cell from the left electrode (anode) to the right electrode (cathode).

This does seem to match , but it's not clear to me. For example as I understand in a Zn|Zn2+||Cu2+|Cu cell:
ΔV_cell=E_red,cathode - E_red,anode = E_red,cu2+|cu - E_red,zn|zn2+ = 0.34V - (-0.76V) = +1.1V
So ΔV_cell is positive, but positive electrical charge moves from the right (cathode) to the left (anode) via an external conductor connecting the two electrodes. This direction is opposite to the one stated above. Does the stated direction refer to the ion movement via the salt bridge (or porous membrane) between the half cells? That would be indeed positive charge into the cathode and negative charge into the anode half cell, so positive charge from anode to cathode. Seipher (talk) 00:04, 6 February 2017 (UTC)

References