Question

What are galvanic cells in terms of oxidation/reduction reactions?

Answer 1

Galvanic cell is a cell consists of 3 parts:
1) Reduction half cell
2) Oxidation half cell
3) Salt Bridge.
Consider a reaction,
`Zn+2Ag^+ rarr Zn^(2+)+2Ag`
so it is represented as,
`Zn` / `Zn^(2+)` `|\ |` `2Ag^+`/ `2Ag`
where, the parallel line shows the salt bridge.
Anode =) `Zn rarr Zn^(2+) +2e^-`
Cathode =) `(2Ag^+ +e^-) rarr 2Ag)*2` (bcoz we have to cancel the `e^-`s so multiply (2) equation by 2)
Now, the required galvanic cell eqn is,
`Zn+2Ag^+ rarr Zn^(2+)+2Ag`