ELECTROCHEMICAL CELL

#.ELECTROCHEMICAL CELL :- 

Example :- Galvanic cell or Voltaic cell or Daniel cell

It converts chemical energy to electrical energy directly i.e., without being converted to mechanical energy.

#. Components of electrochemical cell :- 

1.) Two half cell

         a.)  Oxidation half cell (left) :

                The half-cell in which oxidation takes place is known as oxidation half-cell.

          b.) Reduction half cell (right) :

                 The half-cell in which reduction takes place is known as reduction half-cell.

2.) Salt bridge :

        A salt bridge maintains electrical neutrality and allows the flow of electric current by completing the electrical circuit.

#. Representation of an electrochemical cell:

1. Anode is written on the left while the cathode is written on the right.
2. Anode represents the oxidation half-cell and is written as: Metal/Metal ion (Concentration)
3. Cathode represents the reduction half-cell and is written as: Metal ion (Concentration)/Metal
4. Salt bridge is indicated by placing double vertical lines between the anode and the cathode
5. Electrode potential is the potential difference that develops between the electrode and its electrolyte. The separation of charges at the equilibrium state results in the potential difference between the metal and the solution of its ions. It is the measure of tendency of an electrode in the half cell to lose or gain electrons.
6. Standard electrode potential: When the concentration of all the species involved in a half cell is unity, then the electrode potential is known as standard electrode potential. It is denoted as E°.