For the following cell combination calculate the standard cell potential and write the overall cell reaction: Cd|Cd2+ and Pb|Pb2+

Question

I don't just want the answers. I want to know the steps and how to do it

Answer 1

First, look up the standard reduction potentials for the species involved:

Cd²⁺ + 2e- ==> Cd .. Eº = -0.403 V (anode - oxidation)

Pb²⁺ + 2e- ==> Pb .. Eº = -0.13 V (cathode - reduction)

Because Pb²⁺ has a higher reduction potential, Pb will become the cathode (reduction) and Cd will be the anode (oxidation).

So, the reaction will be:

Pb²⁺ + Cd ==> Pb + Cd²⁺

One way to calculate Eºcell is cathode - anode:

Eºcell = -0.13 V - (-0.403 V)

Eºcell = 0.273 V