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Question 14.41

Posted: Fri Mar 16, 2018 9:49 pm
by 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.

Re: Question 14.41

Posted: Fri Mar 16, 2018 10:10 pm
by Kellina Tran 2I
I’m also confused, since our notes say that we should always make the lower concentration the product

Re: Question 14.41

Posted: Fri Mar 16, 2018 10:25 pm
by 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?

Re: Question 14.41

Posted: Fri Mar 16, 2018 11:15 pm
by Justin Folk 3I
WHat's this about concentration?

Re: Question 14.41

Posted: Sat Mar 17, 2018 12:08 am
by 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?

Re: Question 14.41

Posted: Sat Mar 17, 2018 11:48 am
by 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 [].

Re: Question 14.41

Posted: Sat Mar 17, 2018 1:37 pm
by 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.