What become of the electric energy provided in electrolysis? In what device is this energy transformation reversed?
In electrolysis, electricity is used to drive a non-spontaneous chemical reaction, causing the separation of substances through the process of decomposition. When an electric current is passed through an aqueous solution or a molten compound, the positive ions are attracted to the negative electrode (cathode), where they gain electrons and are reduced. At the same time, the negative ions are attracted to the positive electrode (anode), where they lose electrons and are oxidized.
So, in electrolysis, the electric energy is used to break down water or other compounds into their constituent elements or ions. For example, during electrolysis of water (H2O), hydrogen gas (H2) is produced at the cathode, and oxygen gas (O2) is produced at the anode.
Now, as for the reverse process, the device that uses the opposite concept is called an electrolytic cell. In this cell, electrical energy is used to drive a non-spontaneous chemical reaction, causing the formation of compounds through the process of electroplating, electrolytic refining, or other similar processes. Electrolytic cells use an external voltage source to provide the energy required to convert ions or elements into new compounds.
In an electrolytic cell, the electric energy is converted into chemical potential energy, allowing the production of new substances or the purification of materials. For example, in the electrolytic refining of copper, impure copper is dissolved in an electrolyte, and a copper electrode is made the cathode. By passing an electric current through the electrolyte, pure copper is deposited on the cathode, while the impurities settle at the bottom.
So, in summary, electrolysis uses electric energy to break down compounds, whereas electrolytic cells use electric energy to produce compounds or refine materials.