Chemistry · Electrochemistry · NEET
It is the study of two things happening together: (1) chemical reactions that make electricity, and (2) electricity that makes chemical reactions happen. The common thread is electrons moving from one substance to another. If that electron movement flows through a wire, you get electric current. So electrochemistry is really the science of "reactions that involve electron transfer plus electric current."
No. Electrolysis is only ONE part of electrochemistry. Electrolysis means using electricity to force a reaction (this happens in an electrolytic cell). The other big part is the opposite: a reaction that produces electricity on its own (this happens in a galvanic or voltaic cell, like a battery). Electrochemistry is the full subject that covers both directions.
Because electric current is just a flow of electrons, and many chemical reactions work by passing electrons from one substance to another. These electron-transfer reactions are called redox reactions. If we arrange a redox reaction so the electrons are forced to travel through an outside wire instead of jumping directly, that flow of electrons IS an electric current. That single idea is the heart of electrochemistry.
Mainly redox reactions — reactions where one substance loses electrons (oxidation) and another gains electrons (reduction). Reactions that do not involve electron transfer (like simple acid-base neutralisation) are not the focus of electrochemistry. So before studying cells and EMF, you must be comfortable with redox basics.
It is a scoring chapter that appears every year. NEET tests it as short, formula-based calculations: cell EMF, the Nernst equation, the relation ΔG° = -nFE°cell, conductivity, molar conductivity, and Faraday's laws of electrolysis. Because the questions are direct and repetitive, learning the basic ideas well gives you almost guaranteed marks.
If the E°cell for a given reaction has a negative value, which of the following gives the correct relationships for the values of ΔG° and Keq?
At 298 K, the standard electrode potentials of Cu²⁺/Cu, Zn²⁺/Zn, Fe²⁺/Fe and Ag⁺/Ag are 0.34 V, -0.76 V, -0.44 V and 0.80 V respectively. On the basis of standard electrode potential, predict which of the following reactions cannot occur?
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Michael Faraday is often called the father of electrochemistry because he discovered the quantitative laws of electrolysis (Faraday's laws). Earlier work by Alessandro Volta (the first battery) and Luigi Galvani also started the field. For NEET, focus on Faraday's laws and the cell concepts rather than the history.
Galvanic (voltaic) cells and electrolytic cells. A galvanic cell uses a spontaneous redox reaction to make electricity (positive E°cell), like a Daniell cell or a battery. An electrolytic cell uses outside electricity to force a non-spontaneous reaction (negative E°cell), like electrolysis of molten NaCl. Knowing this difference is a common NEET question.
Yes. Every electrochemical process is a redox reaction, where oxidation (loss of electrons) and reduction (gain of electrons) happen at two separate electrodes. If you are weak in identifying oxidation numbers and which species is oxidised or reduced, learn redox basics first — it makes the whole chapter easy.
The most tested are E°cell = E°cathode - E°anode, ΔG° = -nFE°cell, the Nernst equation, ΔG° = -RT ln Keq (to find equilibrium constant), molar conductivity Λm = κ × 1000 / c, and Faraday's laws (Q = It, moles of electrons = Q/F). These are direct, formula-based marks.
