what is principle and workin of galvanic cell??????????
Galvanic cell (Voltaic cell) is a device to produce electrical energy at the cost of chemical reaction.
It is consist of two electrodes dipped into electrolytes. Thus the metal from the surface of the metal goes into electrolyte solution as ion and left electrons on the electrode. Extent of this ionisation is different for different metals. Electrolytes are connected by salt bridge. Now if two electrodes are connected by external conductor, flow of electricity is obtained.
e.g.
If we dip zinc in zinc sulphate and copper into copper sulphate and connect the two electrolytes by salt bridge, electricity will be obtained on connecting zinc and copper electrode by conductor. Zinc acts as negative electrode and copper acts as positive electrode.
Ultimate cell reaction is
Zn + CuSO4 = Cu + ZnSO4
It is consist of two electrodes dipped into electrolytes. Thus the metal from the surface of the metal goes into electrolyte solution as ion and left electrons on the electrode. Extent of this ionisation is different for different metals. Electrolytes are connected by salt bridge. Now if two electrodes are connected by external conductor, flow of electricity is obtained.
e.g.
If we dip zinc in zinc sulphate and copper into copper sulphate and connect the two electrolytes by salt bridge, electricity will be obtained on connecting zinc and copper electrode by conductor. Zinc acts as negative electrode and copper acts as positive electrode.
Ultimate cell reaction is
Zn + CuSO4 = Cu + ZnSO4