Hi. I myself am confused about why the transfer of
electrons from a more reactive element to less reactive element can
result in the production of electrical energy. Would someone please
explain? Chanced upon this question in the TYS too.
Do reply asap because I want to understand the concept before
submitting my TYS booklet to my teacher. And thanks bonkysleuth for
raising this question up!
A more reactive metal (eg. Na) wants to oxidize itself (ie.
throw away it's valence electrons) to a more stable cationic
state.
But someone has to accept the electrons, or else the
reactive metal (eg. Na) will not be allowed to anyhow throw
away its electrons.
But no worries, a less reactive metal cation (eg. Cu2+) is
here, willing to (or rather, 'bullied' into) accepting the
electrons. So if Cu2+ accepts the electrons at the cathode, and Na
throws away the electrons at the anode, then
[reduction at cathode] Cu2+ + 2e- ---> Cu
[oxidation at anode] 2Na ---> 2Na+ + 2e-
Now, you realize that the electrons cannot magically 'teleport'
from the anode to the cathode. They have to travel or flow
within a metal wire (that connects anode to cathode).
The rate of flow, of these electrons, in the external wire,
is what we call "current".
Comprehende liao? anpanman and
bonkysleuth?
