[Red_CCF]

If I have 2 voltaic cells and connect the anode of one voltaic cell to the cathode of the other cell but NOT connecting the two cells together, the circuit would not be complete and the redox reaction would not go. What I'm wondering is why this is so? I've been explained that charge builds up somehow in one of the electrodes, can anyone verify this? If so how does charge build up?

Here's a sketch of the battery hookup

battery one (cathode)      <-------|
battery one (anode)-unused         |
                                             load
battery two (cathode)-unused      |
battery two (anode)        >-------|


I know this may sound a bit like a physics question but I'm really interested to know the chemical side of this question, like what actually happens to the oxidizing and reducing agents and the electrolyte after we connect the cells so that the redox reaction does not go

Thanks for any help that you can provide

[Mitch]

The only time you'll see work done is if you close the circuit. Open circuits do no work, thus no chemistry.

You now have increased the potential of your system. Like stacking two blocks on top of each other.

At the exact moment you do this, you do move around some electrons, but the whole process is less interesting than you think and occurs on a very fast time scale. If you really want to know more about it let me know, because I don't know off the top my head and will have to go find my freshman physics book.

[Red_CCF]

The only time you'll see work done is if you close the circuit. Open circuits do no work, thus no chemistry.

You now have increased the potential of your system. Like stacking two blocks on top of each other.

At the exact moment you do this, you do move around some electrons, but the whole process is less interesting than you think and occurs on a very fast time scale. If you really want to know more about it let me know, because I don't know off the top my head and will have to go find my freshman physics book.

Thanks for the reply

My dad tried to explain this to me but I'm not sure if it's right since he hasn't touched this for 20+ years.
He said that, in a copper - zinc cell with NO3- ion as the anion, the NO3- ion would repel the electrons at the cathode because the presence of electrons produces an excess charge (as the electrons don't originate in the same battery, they are extra). But my question is, if there is an excess negative charge then how come zinc ion isn't attracted to balance things out? Is it because it's balanced already and wouldn't move? Also how come the NO3- ion doesn't repel the electrons all the way back but just enough so that it stays on the electrode?

Thanks