Q Explain Working of Galvanic Cell?

Ans. There are several types of electrochemical cells. One type of electrochemical cell is called a galvanic cell. (A battery is a galvanic cell that is used to do work.)

In this cell, magnesium and copper are the two metal electrodes. They form a metal couple, represented by Mg/Cu. Magnesium, being more reactive than copper, gives up electrons more readily. Thus, magnesium atoms give up electrons that flow from magnesium to copper in the external circuit. When these electrons flow throw the external wire, they illuminate the light bulb.

Let's take a look at the oxidation and reduction half reactions that occur in this galvanic cell:

Magnesium gives up electrons and forms Mg²⁺ cations. This, this is the electrode that is the anode where oxidation takes place. This oxidation half-reaction is:
Mg ->  Mg⁺² + 2e^-

• Copper receives electrons and therefore becomes the electrode that is the cathode where the reduction reaction occurs. This reduction half-reaction is:
  Cu⁺² + 2e^{- ->} Cu

As the blue copper ions are reduced, they are deposited on the copper metal cathode strip. Consequently, the copper sulfate solution (CuSO₄) becomes less blue as the reaction proceeds. The positive sodium ions and the negative chloride ions in the salt bridge restore the charge balance in the individual beakers