Adding water [ENDORSED]

[smurphy1D]

If pure water is added to either a cathode or anode, would it change the E at all?

[romina_4C]

Adding pure water to the cathode or to the anode would decrease the concentration at the cathode/anode, thus increasing the cell potential because theres a bigger difference between the concentration of the anode/cathode (only if you only dilute one, not if you dilute both the same amount).

[Anuradha S 1F]

I don't think that's correct. According to class notes, when concentration decreases (ie when pure water is added), cell potential will decrease. Not sure about the reasoning, so if anyone knows, please comment!

[Adriana_4F]

This is a bit confusing, someone please clarify!

[Chem_Mod]

Adding pure water to the cathode or to the anode would decrease the concentration at the cathode/anode, thus increasing the cell potential because theres a bigger difference between the concentration of the anode/cathode (only if you only dilute one, not if you dilute both the same amount).

This answer is not completely correct. It's best not to make sweeping generalizations and instead think about it conceptually: Increasing the concentration gradient increases the cell potential. Let's take a simple case of a concentration cell.
1. If you dilute the solution at the cathode (higher concentration initially), you decrease its concentration. This makes the concentrations at the anode and cathode more similar. This decreases the concentration gradient and thus the cell potential.
2. If you dilute the solution at the anode (lower concentration initially), you decrease its concentration. This makes the concentrations at the anode and cathode more different. This increases the concentration gradient and thus the cell potential.