Question

A voltaic cell consists of a strip of cadmium metal in a solution of Cd(NO3)2 in one beaker, and in the other beaker a platinum electrode is immersed in a NaCl solution, with Cl2 gas bubbled around the electrode. A salt bridge connects the two beakers.

Write the equation for the overall cell reaction. (Use the lowest possible coefficients. Include states-of-matter under SATP conditions in your answer.)

Answer 1

At the anode (Cd) you have
Cd ==> Cd^2+ + 2e with Eo = 0.403 (as written) which is an oxidation.
At the cathode (Pt/Cl2) you have
Cl2 + 2e ==> 2Cl^- with Eo = 1.36 (as written) which is a reduction.
Add the two equation to obtain the cell reaction and add the two Eo values to obtain the cell potential. You may add the phases to the reaction.

Answer 2

y don't you use Pt for the second equation?

Answer 3

would it be this?

Cd(s) + Cl2(g) + 2e==> Cd^2+(aq) + 2e + 2Cl^-(aq)

Answer 4

Pt is an inert electrode and is used because Cl2, being a gas, is not conductive.
The equation you wrote is correct if you omit the 2e on each side. The voltage is 1.360 + 0.403 = ?