posted by LT on .
Which statement is true for the cell as it discharges?
Zn | Zn2+(1 .0 M) || Sn2+(1.0 M) | Sn
(A) Oxidation occurs at the tin electrode.
(B) Electrons will flow from the tin electrode to the zinc electrode.
(C) The concentration of Zn2+ will increase.
(D) The mass of the tin electrode will decrease.
Hint: The cell reaction is:
Zn + Sn^+2 ==> Zn^+2 + Sn
would it be A because it is going from Zn to Zn^+2
never mind that wouldnt be right i was looking at the wrong thing
well it cant be A or C so i think that it would be B
You're partly right and partly wrong. It can't be A but it isn't B. It is C.
Look, here is how all of the cells that you draw operate.
I'll use this cell as an example.
Zn is oxidized. We put the metal being oxidized on the left. So the left electrode is the anode, it is giving off electrons, the electrons build up on the electrode, they repel each other because like charges repel, they move through the outside wire connection to the Sn electrode where they give two electrons to the Sn^+2 to become Sn metal. The Sn electrode is the cathode. So Zn is going into solution, Sn^+2 is coming out of solution (and plating Sn metal onto the Sn electrode.) So the Zn electrode is negative and the Sn electrode is +. So you keep this picture in your mind, then run down the answers and see which is right.
You know A can't be right because oxidation occurs at the Zn electrode.
You know B can be right because electrons are flowing from Zn to Sn.
You know C must be right because Zn metal is going into solution to produce those excess electrons that move through the outside wire to the cathode.
You know D can't be right because Sn^+2 ions are gaining two electrons and plating out onto the Sn metal.