What energy conversion takes place in a galvanic cell?
The energy conversion that takes place in a galvanic cell is an chemical to electrical change.
Galvanic cells are cells that consist of two dissimilar metals in common contact with an electrolyte. Because the two metals have different reactivities with the electrolyte, current will flow when the cell is connected to a closed circuit.
Galvanic cells derive their energy from the spontaneous redox reactions that take place within the cell.
An example of a galvanic cell can be observed in the following reaction:
The electrodes are Pb(s), and PbO2(s). The supporting electrolyte is sulfuric acid. Here are the important reactions:
Anode: Pb(s) + HSO4- → PbSO4(s) + H+ + 2e-
lead is oxidized from the 0 to the +2 state
Cathode: PbO2(s) + HSO4- + 3H+ + 2e- → PbSO4(s) +2H2O
lead is reduced from the +4 to the +2 state
Net reaction: Pb(s) + PbO2(s) + 2H+ + 2HSO4- →2PbSO4(s) + 2H2O