But let's say there is a voltaic pile. If the reaction is Zn + 2H+ --> Zn2+ + H2, between zinc and hydrogen, what is copper used for? Why do we need it at all if it's not reduced, and hydrogen ions are the ones that are reduced? If the whole point is so that the electrons given off can travel through an external circuit to meet the copper electrode ... then does that mean copper is an INERT electrode in this case? since it does not participate in redox reactions and only acts as an.. electron transfer-er to the elctrolyte?
(Please be patient with me. I know I am confused and ignorant beyond belief, but I just have to understand this!)
Also, in my chemistry class, we stacked a voltaic pile like this
Al
Na2CO3 (paper towel soaked in it)
Cu
Al
Na2CO3
Cu
etc..
And it conducted electricity! What's going on? I know that Aluminum lost 3 electrons to become Al3+, and that travelled through the electrolyte... but Na2CO3 is no acid, there's no H+. So if the reaction is between Aluminum and hydorgen ions, does that mean the hydrogen ions come from water? (Which does not have a great amount of supply of it). Or does it react with something else?