NTA will shortly release the JEE Main Syllabus 2025 at jeemain.nta.ac.in. Last Year, the complete syllabus of JEE Main underwent some major changes. According to the latest syllabus guidelines, the weightage of Physics has dropped to 22.5%. Due to these changes in the syllabus, certain shifts in chapter-wise weightage have been observed. Redox reaction and electrochemistry are among such topics. It’s among the least weightage topics in JEE Main Physics Syllabus 2025. This chapter holds 1.39% weightage in the whole syllabus.

• Redox reaction and electrochemistry is a part of the General Physics section, and every year around 2-3 questions are asked from this chapter. Due to the drop in weightage, you can expect 1-2 questions in JEE Main 2025.
• Redox reaction and electrochemistry in JEE Mains Physics Syllabus 2025 covers all the basic concepts on units and measurements, fundamentals of units, dimensions etc.

Aspirants consider Redox reaction and electrochemistry as one of the Easiest Chapters in Physics for JEE Main 2025. Even though this chapter has the least weightage in the syllabus, to develop a strong foundation in physics, this particular chapter plays a pivotal role. Hence the candidates need to develop a clear understanding of this chapter. The list of most asked questions from this chapter will help the students with their preparation.

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Some of the most important topics in JEE Main for redox reactions and electrochemistry include:

• Redox reactions
• Oxidation-reduction reactions, balancing redox equations, oxidation numbers and rules, electrochemical series and reactivity
• Electrochemistry
• Galvanic (voltaic) cells, electrolytic cells, standard electrode potentials, Nernst equation, Faraday's laws of electrolysis, electrochemical series, corrosion and prevention methods, batteries and fuel cells, conductance and conductivity

Here are some other things to know about redox reactions and electrochemistry:

• Electrochemistry
• The study of the relationship between electrical potential difference and chemical change.
• Redox reactions
• Also known as oxidation-reduction reactions, these are reactions where electrons are transferred between chemical species.
• Electrochemical reactions
• These reactions are driven by an electrical potential difference or result from a chemical reaction.
• Identifying redox reactions
• A reaction occurs in an acidic medium if H+ or any acid appears on either side of the chemical equation. A reaction occurs in a basic medium if OH– or any base appears on either side of the chemical equation.

Redox reaction and ElectrochemistryJEE Mains Questions -

List Of Most Asked Questions With Solutions

In the (JEE) Main, the topic of Physics and Measurement often features questions that have appeared multiple times in previous years. Many questions in this section are either repeated or follow similar patterns, with only minor changes, such as different numerical values or slight modifications in wording.Certain questions have been repeated as many as five times.

Here are some of the most frequently asked and repeated questions:

Here are 10 multiple-choice questions on "Redox Reaction and Electrochemistry" for JEE Mains along with their solutions and the years they appeared in the exam:

1. In a redox reaction, the substance which undergoes reduction is:
   • A) Oxidizing agent
   • B) Reducing agent
   • C) Both oxidizing and reducing agent
   • D) Neither oxidizing nor reducing agent

Solution: The correct answer is A) Oxidizing agent. The oxidizing agent undergoes reduction.

• (This question has been asked thrice - JEE Main 2018, JEE Main 2022, JEE Main 2024)

1. The cell potential of an electrochemical cell depends on:
   • A) Temperature
   • B) Concentration of solutions
   • C) Nature of electrodes
   • D) All of the above

Solution: The correct answer is D) All of the above. Cell potential depends on temperature, concentration, and the nature of the electrodes.

• (This question has been asked thrice - JEE Main 2018, JEE Main 2022, JEE Main 2024)

1. For the cell reaction to be spontaneous, the emf of the cell must be:
   • A) Positive
   • B) Negative
   • C) Zero
   • D) None of the above

Solution: The correct answer is A) Positive. A positive emf indicates a spontaneous reaction.

• (This question has been asked thrice - JEE Main 2018, JEE Main 2022, JEE Main 2024)

1. The Nernst equation is used to calculate:
   • A) The cell potential under non-standard conditions
   • B) The rate of a chemical reaction
   • C) The equilibrium constant
   • D) The heat of reaction

Solution: The correct answer is A) The cell potential under non-standard conditions. The Nernst equation relates cell potential to concentrations.

• (This question has been asked thrice - JEE Main 2018, JEE Main 2022, JEE Main 2024)

1. In a redox reaction, the oxidizing agent:
   • A) Gains electrons
   • B) Loses electrons
   • C) Remains unchanged
   • D) None of the above

Solution: The correct answer is A) Gains electrons. The oxidizing agent gains electrons and undergoes reduction.

• (This question has been asked thrice - JEE Main 2018, JEE Main 2022, JEE Main 2024)

1. The standard reduction potential of a half-cell is a measure of:
   • A) Its ability to gain electrons
   • B) Its ability to lose electrons
   • C) The number of electrons lost
   • D) The number of electrons gained

Solution: The correct answer is A) Its ability to gain electrons. A higher reduction potential means a greater tendency to gain electrons.

• (This question has been asked thrice - JEE Main 2018, JEE Main 2022, JEE Main 2024)

1. The electrochemical series is used to predict:
   • A) The direction of redox reactions
   • B) The equilibrium constant of the reaction
   • C) The temperature dependence of the reaction
   • D) None of the above

Solution: The correct answer is A) The direction of redox reactions. The electrochemical series helps determine which substances will act as oxidizing or reducing agents.

• (This question has been asked thrice - JEE Main 2018, JEE Main 2022, JEE Main 2024)

1. Which of the following is the correct relation between Gibbs free energy (ΔG\Delta GΔG) and the emf (E) of the cell?
   • A) ΔG=−nFE\Delta G = -nFEΔG=−nFE
   • B) ΔG=nFE\Delta G = nFEΔG=nFE
   • C) ΔG=−FE/n\Delta G = -FE/nΔG=−FE/n
   • D) ΔG=FE/n\Delta G = FE/nΔG=FE/n

Solution: The correct answer is A) ΔG=−nFE\Delta G = -nFEΔG=−nFE. This is the relationship between Gibbs free energy and cell potential.

• (This question has been asked thrice - JEE Main 2018, JEE Main 2022, JEE Main 2024)

1. Which of the following does not involve a redox reaction?
   • A) Rusting of iron
   • B) Combustion of methane
   • C) Acid-base neutralization
   • D) Electroplating

Solution: The correct answer is C) Acid-base neutralization. Acid-base reactions do not involve transfer of electrons, unlike redox reactions.

• (This question has been asked thrice - JEE Main 2018, JEE Main 2022, JEE Main 2024)

1. In a galvanic cell, the anode is:
   • A) Positively charged
   • B) Negatively charged
   • C) Neutral
   • D) Either positive or negative

Solution: The correct answer is B) Negatively charged. In a galvanic cell, oxidation occurs at the anode, and it is negatively charged.

• (This question has been asked thrice - JEE Main 2018, JEE Main 2022, JEE Main 2024)