It is a well known fact that energy menifests itself in different forms which are interconvertible into one another. Among different forms of energy, the electrical energy plays a very significant role in our daily life. Many chemical transformations and industrial processes are based on electrical energy and its relationship with chemical energy. There are large number of spontaneous redox reactions which form the basis of production of electrical energy. The device in which such chemical processes are carried out is called electrochemical cell or galvanic cell. For example, Daniell cell is based on the following redox reaction:
Cu2(aq) + Zn(s) à Cu(s) + Zn2+ + Electrical Energy
At the same time many of the non-spontaneous redox reactions can be made to occur by the use of electrical energy. Some examples are:
The branch of chemistry which deals with the study of relationship between electrical energy and chemical energy and interconversion of one form of energy into another is called electrochemistry. Electrochemistry is very vast and interdisciplinary branch of chemistry which finds tremendous applications. Its study is very important as it helps in the development of new technologies which are economical and environment-friendly. In this unit, we shall focus on the study of some aspects of electrochemical cells, batteries and fuel cells, etc.