A galvanic cell behaves like an electrolytic cell under certain conditions, primarily when an external voltage or potential is applied to it. This phenomenon occurs when the potential applied externally is greater than the cell potential of the galvanic cell.
In a galvanic cell, spontaneous chemical reactions generate electrical energy, causing electrons to flow from the anode to the cathode through an external circuit. This flow of electrons creates an electric current. The cell potential, also known as the electromotive force (EMF) or voltage, is positive, and the direction of electron flow is predetermined by the chemical reactions occurring at the electrodes.
However, if an external voltage is applied to the galvanic cell in the opposite direction of the spontaneous reaction, it can overcome the cell potential and force the non-spontaneous reaction to occur. This external voltage effectively reverses the direction of electron flow and drives the cell to operate as an electrolytic cell.
In an electrolytic cell, electrical energy is used to drive non-spontaneous chemical reactions. This process requires an external power source to supply the necessary energy to overcome the energy barrier associated with the reaction. As a result, electrons flow from the external power source to the anode (the electrode where oxidation occurs) and then through the cell to the cathode (the electrode where reduction occurs).
In summary, a galvanic cell behaves like an electrolytic cell when an external voltage is applied in the opposite direction of the spontaneous reaction, causing the cell to operate in reverse and drive non-spontaneous chemical reactions.
