What distinguishes voltaic cells from electrolytic cell?
The main difference between voltaic cells and electrolytic cells lies in their purpose and the flow of electron movement.
A voltaic cell, also known as a galvanic cell, is an electrochemical cell that converts chemical energy into electrical energy. It generates an electric current by harnessing a spontaneous redox reaction. In a voltaic cell, two different metal electrodes are immersed in an electrolyte solution. One electrode acts as the anode (site of oxidation) where electrons are lost, while the other electrode serves as the cathode (site of reduction) where electrons are gained. The flow of electrons occurs from the anode to the cathode, creating a potential difference or voltage. Voltaic cells are commonly found in batteries and power sources.
On the other hand, an electrolytic cell is an electrochemical cell that uses electrical energy to drive a non-spontaneous redox reaction. It essentially functions in the opposite direction of a voltaic cell. In an electrolytic cell, a direct current (DC) is applied from an external power source, which forces a non-spontaneous reaction to occur. The anode becomes the positive electrode (site of oxidation), attracting negatively charged ions from the electrolyte. The cathode becomes the negative electrode (site of reduction), attracting positively charged ions. This process allows for the desired chemical reaction to take place. Electrolytic cells are commonly used in electroplating, metal refining, and the production of various chemicals.
In summary, the main distinctions between voltaic cells and electrolytic cells are:
1. Purpose: Voltaic cells convert chemical energy into electrical energy, while electrolytic cells facilitate a non-spontaneous reaction using electrical energy.
2. Flow of Electrons: Voltaic cells have an internal spontaneous flow of electrons from the anode to the cathode, while electrolytic cells require an external source to drive the electron flow from the cathode to the anode.