What is the electrode reactions?
The reactions that occur due to the transfer of electrons to or from the electrode
In galvanic cells, the oxidation process occur at the anode and take – ve sign
While the reduction process occur at the cathode and take + ve sign
This is the reverse of electrolytic cell
The electrode can write by its name M/Mc+n
If emf +ve sign means spon. Process, ∆G= -ve
If emf -ve sign means non-spon. Process, ∆G = +ve
Since, emf = L + R
Measurements of E0, for pure metals- P 1 atm- activity of solution =1
– express the potential of electrodes by reduction potential (ما لم ينص غي غير ذلك)
e.g: E0 = - 0.76 v for Zn
That is mean that E0 (Zn+2/Zn) = - 0.76 v
Applications of electrochemistry:
1- Electrochemical batteries
2- Fuel cells
3- Metal finishing
4- Refining and production of metal
5- Metals and material processing
6- Corrosion control
8- Determination of physical parameters.
E.g. K, equilibrium constant, E0 stander cell potential, PH , reaction rates and …..
9- Titration (coductomertric, potentiometric)
10- Recycling of industrial process