[Sam1988]

Simple cell


1) With a simple cell such as zinc and copper, why do the electrons travel through the wire and around to the copper when zinc is oxidised, instead of the zinc giving electrons to the positive ions in the solution straight away? Is it a more efficient way of electrons being transferred?

I understand the positive ion in solution would be reduced on the copper electrode.

2) does the electrolyte matter? Would the cell still work if the ions present were more reactive than both metal electrodes. For instance if the electrolyte was a NaCl solution, would electrodes of silver and copper work even though they are less reactive than sodium and hydrogen?

[Borek]

1) With a simple cell such as zinc and copper, why do the electrons travel through the wire and around to the copper when zinc is oxidised, instead of the zinc giving electrons to the positive ions in the solution straight away? Is it a more efficient way of electrons being transferred?

You are perfectly right they will react directly - given chance. We design the cell to keep things that could react directly separated, so that electrons have to flow through the wire.

2) does the electrolyte matter? Would the cell still work if the ions present were more reactive than both metal electrodes. For instance if the electrolyte was a NaCl solution, would electrodes of silver and copper work even though they are less reactive than sodium and hydrogen?

Yes, electrolyte matters, choosing the right one is often key to the success. At the same time presence of very stable Na⁺ doesn't mean you deal with a highly reactive sodium.

[Sam1988]

Thank you for replying Borek.

As you said in your reply quoted below the electrode would react directly with the electrolyte instead of electrons going to the other electrode if it could.
In a zinc/copper cell what electrolyte could you not use and why? Or which do you use and why?

“You are perfectly right they will react directly - given chance. We design the cell to keep things that could react directly separated, so that electrons have to flow through the wire.” Borek


Thanks Chris