Would this be a good reducing agent? Given the following standard reduction potential: Cu2+(aq) + e- → Cu+(aq) Eo = 0.15V Fe3+(aq) + e- → Fe2+(aq) Eo = 0.77V
When standard electrode potentials are listed -ve to +ve like this you find the most powerful reducing agents at the top right of the list.
They are good reducers because they have a strong tendency to release electrons.
Similarly, you will find the strongest oxidising agents at the bottom left of the table.
They are good oxidisers because they have a strong tendency to take in electrons.
A useful rule of thumb is that "bottom left will oxidise top right".
Or you can say "top right will reduce bottom left.
When 2 half-cells are connected it is the most +ve half-cell that will take in the electrons.
In this case you can see that the
You can see that
The cell reaction is therefore:
To get the emf of the cell subtract the least +ve
If you are familiar with the concept of free energy then:
For a reaction to be feasible the value of