Electrochemical or Galvanic cell
“Electrochemical cell or Galvanic cell is a device in which a spontaneous redox reaction is used to convert chemical energy into electrical energy i.e. electricity can be obtained with the help of oxidation and reduction reaction”.
(1) Characteristics of electrochemical cell: Following are the important characteristics of electrochemical cell,
(i) Electrochemical cell consists of two vessels, two electrodes, two electrolytic solutions and a salt bridge.
(ii) The two electrodes taken are made of different materials and usually set up in two separate vessels.
(iii) The electrolytes are taken in the two different vessels called as half - cells.
(iv) The two vessels are connected by a salt bridge/porous pot.
(v) The electrode on which oxidation takes place is called the anode (or – ve pole) and the electrode on which reduction takes place is called the cathode (or + ve pole).
(vi) In electrochemical cell, ions are discharged only on the cathode.
(vii) Like electrolytic cell, in electrochemical cell, from outside the electrolytes electrons flow from anode to cathode and current flow from cathode to anode.
(viii) For electrochemical cell,
(ix) In a electrochemical cell, cell reaction is exothermic.