Building A Galvanic Cell Series

[Pontiuth Pilate]

I have strips of common metals (copper, nickel, iron, zinc and aluminum) as well as nitrate solutions of each of these. I want to build two batteries in series by connecting two galvanic cells with a third wire. Schematic:

Some questions:

1. Do I need a third salt bridge between the cells?

2. Do I need to take into account the two reactions, or three including the one occuring across the wire between the two cells?

3. What metals should I use to achieve the maximum possible voltage? Will the voltages sum across the series or am I doing something wrong?

 

[luiz]

1-No
2-No
3-Use metals with little resistence. It's easy to find the resistivity of nearly every metal on Earth. And yes, the voltages will sum (minus the losses of course).

 

[Perfection]

3. No you use the metal that is most easily oxidized and the cation that is most easily reduced.

I'd need the oxidation numbers on the metal cations before I could determine which one to use, for example do you have Iron(III) Nitrate or Iron(II) Nitrate?

Just a word about aluminum, if you decide to use the aluminum as the anode (which will work pretty good) make sure you scratch it up really good beforehand to remove the protective oxide coating.