Question 14.41

[Arjun Sharma 1D]

For question 14.41 part (a), why is the Cu2+ with lower concentration the anode and Cu2+ with higher concentration the cathode? I thought you would want it the other way around since it would flow from high concentration to low concentration and you would want that to be anode to cathode.

[Kellina Tran 2I]

I’m also confused, since our notes say that we should always make the lower concentration the product

[Arjun Sharma 1D]

Yeah it's weird too cause the lower concentration ends up in the product according to the solution manual. Maybe it's because you have to flip the sign of the anode?

[Justin Folk 3I]

WHat's this about concentration?

[Arjun Sharma 1D]

In a concentration cell, why would you want your lower concentration reactant on the anode and the higher one on the cathode?

[melissa carey 1f]

You want e- to flow anode to cathode. At the anode Cu(s) > Cu2+ + 2e-. At the cathode Cu2+ + 2e- > Cu(s). So the anode [] is a product and cathode [] is a reactant. Since you want postive E and Q=P/R, so, using the eq, you can see that anode should always have lower [].

[Yu Chong 2H]

The flow of electrons is not the same as the "flow" of the Cu2+. The electrons will flow towards the side with higher concentration of Cu2+ so that the copper ions there can get reduced to form Cu(s) and therefore reducing the concentration of Cu2+ in that cell.