Reactions are a crucial part of Chemistry. But, what is an electrochemical reaction, and how is it unique? Let us try to discover the answer. Any process either caused or supplemented by the passage of an electric current and engulfing, primarily, the transfer of electrons between two substances – one being liquid and the other being solid - is an electrochemical reaction. The three main components of the reaction are:
The presence of a solution where redox can occur is mandatory. Electrochemical reactions generally take place in water to facilitate the movement of electrons and ions.
The presence of a conductor is compulsory for electrons to get transferred. The conductor is usually some wire so that electrons can move from one site to another.
The ions must be able to move through some form of a salt bridge that facilitates ion migration.
The Process of Electrochemical Reaction
The interactions of matter related to the flow of an electric current depend upon the negatively charged electron characteristics. An electron is a fundamental part of electricity, and hence has an affinity or attraction for positively charged particles of matter, protons. This affinity is synonymous with the chemical affinity that particles exhibit among themselves. All chemical reactions result from the shift in atoms' electron structure, wherein free electrons can combine with particles of matter (reduction) or get released by them (oxidation). The substances that take part in the electrochemical process are called electrolytes or ionic conductors. Electrons are available in considerable quantities in a relatively mobile state only in substances called electronic conductors, among which metals are most crucial. Thus, an electronic conductor must be present as the primary component of any system in which electrochemical reactions occur.
Moreover, the availability of electrons in a conductor is limited by energy distribution to such a degree that electrochemical reactions only occur near the electronic conductor's surface. Hence, electrochemical reactions typically happen at the common boundary between an electronic conductor, that is, an electrode, and an ionic conductor of electricity - an electrolytic solution. It is important to note that electrochemical processes will take place only to the degree that electricity can pass through such a system as a whole. As such, the system must form a closed loop. In a nutshell, if at one metal-solution interface, electrons are coming out of the metal, thereby reducing a component of the solution, there has to be a second-metal solution interface wherein electrons are going inside the metal in the process of oxidation. The two electrodes and ionic conductor in between represent an electrochemical cell. Let us try and analyze the concept of a cell in detail.
Application of Electrochemical Cell
An electrochemical cell is a tool that can create energy from the chemical reactions happening within it or utilize the electrical energy supplied to it to facilitate chemical reactions in it. A typical example of an electrochemical cell is a standard 1.5-volt cell used to power many electrical appliances such as TV, remotes, etc. The main applications of an electrochemical cell are –
The use of electrolytic cells is common in the electro-refining of non-ferrous metals.
The production of high-purity zinc, aluminium, and copper involves the use of electrolytic cells.
They are also used in the electro-winning of non-ferrous metals.
It is possible to extract metallic sodium from molten sodium chloride by placing the latter in an electrolytic cell with an electric current.
Example of an Electrochemical Reaction
An electrochemical reaction is a spontaneous reaction used to generate an electric current in an electrochemical cell. An example of an electrochemical reaction is when gaseous oxygen and hydrogen combine in a fuel cell to create water and energy, typically a combination of heat and electrical energy. An electrochemical cell can be represented as – Zn/Zn2+ || Cu2+ /Cu
Electrochemistry is that branch of physical chemistry that engages with the interconversion of chemical energy and electrical energy. Electrochemistry is a salient part of the broader discipline of Chemistry. It is concerned with the relationship between electrical potential, a measurable and quantitative phenomenon, and identifiable chemical change, with either electrical potential as an outcome of a particular chemical change or vice-versa. There are numerous electrochemistry applications. We have mentioned some of them below –
An electrochemical reaction is a driving force behind batteries as they are made of one or more galvanic cells or fuel cells. We use batteries in all spheres of life, and hence their utility.
An electrolytic cell for electroplates. Electroplating has applications such as corrosion protection of certain metals, jewellery production, etc.
Electrochemistry is necessary for several industries like the chlor alkali industry.
Electrochemistry is a fascinating discipline. It is necessary to learn about electrochemical reactions because they have immense academic as well as practical value. Understanding the responses enables us to understand the functioning of mundane things like a battery or cell.