Electrochemical cell

Introduction :
Electrochemical is the learning of production of electricity from energy released during the spontaneous chemical reaction and the use of electrical energy to bring about non spontaneous chemical transformation. Important equally of the abstract and useful consideration. A large number of metal, sodium hydroxide, chlorine, fluorine and many other chemical are produce by electrochemical methods. Batteries and fuel cells converted chemical energy into electrical energy and are used to a large scale in various instrument and devices.

Daniel cell of electrochemical cells:

An electrochemical cell is used to convert the electrical energy to the chemical energy.We had studied the construction and functioning of Daniell cell. This group converts the chemical energy unconventional through the redox reaction.
Zn(s) +Cu²⁺ (aq)   `harr`  zn²⁺ (aq) +Cu(s)
 
To electrical energy and has an electrical potential equal to 1.1 V when concentration of Zn2+ and Cu2+ ions is unity such a device is called a galvanic or voltaic cell. If an internal opposite potential is applied in the galvanic cell and decreased slowly, we find that the reaction continues to take place till the operating voltage reaches stops altogher and no current flows through the cell.
                Any additional enlarge in the external possible gain again create the response but in the opposite direction. It now functions as an electrolytic cell, tool for using electrical energy to carrying non spontaneous chemical reaction. Equally types of cell are given up significant and we shall study some of their salient feature in the following pages.

Classification of the electrochemical cell:

Oxidation-reduction or redox reactions obtain position in electrochemical cells. Generally two classifications of electrochemical cells. Spontaneous reactions occur in galvanic (voltaic) cells; no unstructured reactions occur in electrolytic cells. Both types of cells include electrodes where the oxidation and decrease reactions occur. Oxidation occurs at the electrode term the anode and decrease occur at the electrode call as cathode.
             A possible difference develops among the electrode and the electrolyte which is call electrode potential. When the concentration of each the class implicated in a partly cell is combination then the electrode potential is well-known as standard electrode potential.