Give the half equations and then the overall balanced equation for Cu^2+/Cu (+0.54V) and Cl2/Cl^-1 (+1.36V)

Firstly we need to start with the half equations. When we write half equations we always started with reduction (gain in electrons): Cu²⁺ + 2e^- → Cu (+0.54V) Cl₂ + 2e^- → 2Cl^-  (+1.36V) It is good practice to write out the standard potential of the cell next to the half equation to make life easier when solving the question. Now that we have the half-equations, we need the overall balanced equation. Recall that the Gibbs Energy needs to be negative for a spontaneous reaction, hence using:  ΔG=-vFE (where v is the number of electrons transfered, F is Faraday's constant and E is the standard potential of the cell) we can see that the standard potential has to be positive. Standard potential is therefore: +1.36V - 0.54V = +0.82V Notice that the Cu²⁺/Cu^- half cell has it's sign inverted (from + to -), we can show this in the overal equation as such: Cu → Cu²⁺ + 2e^-  (-0.54V) Cl₂ + 2e^- → 2Cl^-   (+1.36V) Overall: Cl₂ + Cu → 2Cl^- + Cu²⁺ The electrons are already balanced, hence this is the overall equation.