What are galvanic cells ? Explain the woriking of a galvanic cell with a neat sketch taking Denicell cell as example.

Explanation

The device in which chemical-energy is converted into electrical . energy is called galvanic cell .or electrochemical cell or voltaic cell. In-a galvanic cell, a redox reaction is carried in an indirect mariner and the decrease in free energy during the chemical pro-cess is made,to appear as electrical energy.
In the Daniell cell a zinc strip is dipped in the `ZnSO_(4)` solution and a copper strip is dipped in the `CuS0_(4)` solution taken in separate be.akers.The two metallic strips which act as electrodes are connected by the conducting wires through Voltmeter. The two solutions, are joined by an inverted U - tube known as salt bridge which contain an electrolyte such as KCI, `KN0_(3)` or `NH_(4)` CI along with gelatin or agar - agar to convert the electrolyte into semi solid paste

The working of the cell can be understand by thefollqwing steps.
(i) Zinc undergoes oxidation to form zipc ions. `Zn(s) rarr Zn_(2+) (aq) + 2e^(-)` oxidation
(ii) The electrons liberated during oxidation are pushed through the connecting wires to copper strip.
(iii) Copper ions move towards copper strip, pick up the electrons and get reduced to copper atoms which. are deposited at the copper strip.
`Cu^(2+) (aq) + 2e^(-) rarr Cu (s)` Reduction.
The transference of electrons from anode (oxidation) electrode i.e., zinc electrode to cathode (reduction electrode i.e., copper electrode) leads to flow of electric current.