Electrolysis is the process by which electrical energy is freed from a substance to produce a charge that generates a non-spontaneous chemical reaction in another substance. An example of electrolysis is the flashlight battery. A negatively charged terminal is placed inside an ionic solution to free electrical energy packets called electrons, which are transferred to a positively charged terminal connected to another substance or object. The electrical energy that is freed through electrolysis does work on the substance or object to which the positive terminal is connected.
In 1834, a scientist named Michael Faraday figured out both the relationship between current and work as well as how to determine the amount of work required to produce the desired reaction. His laws, known as Faraday’s Laws of Electrolysis, provide engineers with formulas to calculate how much electrical energy can be freed from a metallic solution by an electrochemical reaction.
Faraday’s First Law of Electrolysis states that the quantity of a substance liberated by electrolysis is a product of the charge delivered to the solution and the electrochemical equivalent of the metal, which is the amount freed by one Coulomb of electricity. A Coulomb is a unit of electrical charge equal to running one amp of current for one second. The First Law of Electrolysis provides a method for calculating the amount of work done on a particular metal by a given amount of electrical charge. Faraday’s Second Law of Electrolysis states that the mass of metal freed by a given electrical charge is proportional to the chemical mass of the metal. The chemical mass of a substance is its molar mass, which can be obtained from the Periodic Table of the Elements. The Second Law of Electrolysis also uses a value called Faraday's Consant to calculate the amount of work required to free a specific amount of metal from a solution.
There are several applications that require an understanding of Faraday’s Laws of Electrolysis. One is electroplating objects, or coating them with metal either to prevent corrosion or just to give them a more attractive appearance. The science of electroplating uses Faraday’s laws to determine how long a current should be applied to a solution to coat the object with a specific amount of metal. Some other applications of electrolysis that require Faraday’s laws are metallurgy, which is the process of removing metals from ores, and electro-refining, which is the process of purifying metals after they have been removed from ores. The formulas provided by the laws are necessary to determine how much time is required to free the metal from the solution using a given current.
Electrolysis uses electric current to free electrical energy, which can be used to do work. If it were not for the laws of Michael Faraday, people would have no way of determining the amount of work that can be done by a given charge on a given mass.