What does Redox Reactions and Electrochemistry cover for NEET Chemistry?

13 lessons: Balancing Redox, Cell Potential Gibbs, Dry Cell Lead Accumulator, Electrochemical Cells, Electrode Potential, Electrolytic Metallic Conduction, EMF Galvanic, Fuel Cells, Kohlrausch Law, Molar Conductivity, Nernst Equation, Oxidation Number and Oxidation Reduction Electronic.

How often has Redox Reactions and Electrochemistry come up in NEET past papers?

Our set of verified past papers has 21 questions from this unit, from NEET 2020, 2021, 2022, 2023, 2024, 2025 and 2026. Each is answered against the official NTA key.

Is the Redox Reactions and Electrochemistry material free?

Yes. All 13 lessons and 104 practice questions are free, with no login needed.

Redox Reactions and Electrochemistry

13 lessons

Topic index in NCERT order

13 of 13 lessons by the NCERT chapter they teach from, in book order. The page is the first printed page of your NCERT book the lesson cites; PYQs are the past NEET questions on that topic.

Class 11 Chemistry, Chapter 7

Oxidation Reduction Electronicp. 2362 PYQs
Oxidation Numberp. 2404 PYQs
Balancing Redoxp. 2461 PYQ
Electrode Potentialp. 2502 PYQs

Class 12 Chemistry, Chapter 2

Electrochemical Cellsp. 314 PYQs
EMF Galvanicp. 341 PYQ
Nernst Equationp. 390 PYQs
Cell Potential Gibbsp. 401 PYQ
Molar Conductivityp. 451 PYQ
Kohlrausch Lawp. 493 PYQs
Electrolytic Metallic Conductionp. 521 PYQ
Dry Cell Lead Accumulatorp. 540 PYQs
Fuel Cellsp. 540 PYQs

Balancing Redox

8 MCQs1 PYQsWorked example

Direct Application (3)Easy Recall (3)Calculation (2)

Cell Potential Gibbs

8 MCQs1 PYQs6 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (1)Concept Trap (1)

Dry Cell Lead Accumulator

8 MCQsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (2)

Electrochemical Cells

8 MCQs4 PYQs2 revision cardsWorked example

Easy Recall (3)Concept Trap (2)Direct Application (3)

Electrode Potential

8 MCQs2 PYQs2 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (1)Concept Trap (1)

Electrolytic Metallic Conduction

8 MCQs1 PYQs3 revision cardsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)

EMF Galvanic

8 MCQs1 PYQs2 revision cardsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (2)

Fuel Cells

8 MCQsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (2)

Kohlrausch Law

8 MCQs3 PYQs4 revision cardsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)

Molar Conductivity

8 MCQs1 PYQs4 revision cardsWorked example

Direct Application (3)Concept Trap (2)Easy Recall (2)Calculation (1)

Nernst Equation

8 MCQs5 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (1)Concept Trap (1)

Oxidation Number

8 MCQs4 PYQsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)

Oxidation Reduction Electronic

8 MCQs2 PYQsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (2)

Past-paper questions from this unit

21 questions from NEET 2020, 2021, 2022, 2023, 2024, 2025, 2026. Answers verified against NTA official keys.

By year in our set: 2020 (3) · 2021 (3) · 2022 (4) · 2023 (3) · 2024 (3) · 2025 (2) · 2026 (3)

Lesson: Electrode Potential

NEET 2026

The standard electrode potential (E°) for the half-cell reaction Fe³⁺ + e⁻ → Fe²⁺ at 298 K is (Given : E°(Fe³⁺/Fe) = −0.04 V and E°(Fe²⁺/Fe) = −0.44 V at 298 K)

1+0.40 V

2+0.76 V

3−0.48 V

4+0.92 V

NTA Answer: Option 2(final)

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Lesson: Kohlrausch Law

NEET 2026

For a salt XY, which is a strong electrolyte, the plot of Λ_m versus √c has a slope of −90.0 S cm² mol⁻³ᐟ² L¹ᐟ² at 298 K. At 0.01 M concentration of XY, the value of Λ_m is 145.0 S cm² mol⁻¹. The limiting molar conductivity of Y⁻ ion (λ°_Y⁻, in S cm² mol⁻¹) at 298 K will be (Given : λ°_X⁺ = 74.0 S cm² mol⁻¹)

180.0

2100.0

390.0

476.0

NTA Answer: Option 1(final)

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Lesson: Oxidation Number

NEET 2026

The correct decreasing order of oxidation state of the underlined atom in each molecule is

1P₄O₁₀ > SO₃ > H₂O

2N₂O₅ > Al₂O₃ > H₂S

3PbO₂ > N₂O₃ > SO₃

4P₄O₆ > Cl₂O₇ > AlH₃

NTA Answer: Option 2(final)

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Lesson: Kohlrausch Law

NEET 2025

If the molar conductivity (Λₘ) of a 0.050 mol L⁻¹ solution of a monobasic weak acid is 90 S cm² mol⁻¹, its extent (degree) of dissociation will be [Assume Λ°₊ = 349.6 S cm² mol⁻¹ and Λ°₋ = 50.4 S cm² mol⁻¹.]

10.215

20.115

30.125

40.225

NTA Answer: Option 4(final)

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Lesson: Oxidation Number

NEET 2025

Consider the following compounds : KO2, H2O2 and H2SO4 The oxidation state of the underlined elements in them are, respectively,

1+4, –4, and +6

2+1, –1, and +6

3+2, –2, and +6

4+1, –2, and +4

NTA Answer: Option 2(final)

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Lesson: Electrochemical Cells

NEET 2024Revised key

Match List I with List II. List I (Conversion) — List II (Number of Faraday required) A. 1 mol of H₂O to O₂ — I. 3F B. 1 mol of MnO₄⁻ to Mn²⁺ — II. 2F C. 1.5 mol of Ca from molten CaCl₂ — III. 1F D. 1 mol of FeO to Fe₂O₃ — IV. 5F Choose the correct answer from the options given below:

1A-II, B-IV, C-I, D-III

2A-III, B-IV, C-I, D-II

3A-II, B-III, C-I, D-IV

4A-III, B-IV, C-II, D-I

NTA Answer: Option 1(revised_final)

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Lesson: Oxidation Reduction Electronic

NEET 2024Revised key

Which reaction is NOT a redox reaction?

1Zn + CuSO₄ → ZnSO₄ + Cu

22KClO₃ + I₂ → 2KIO₃ + Cl₂

3H₂ + Cl₂ → 2HCl

4BaCl₂ + Na₂SO₄ → BaSO₄ + 2NaCl

NTA Answer: Option 4(revised_final)

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Lesson: Electrochemical Cells

NEET 2024Revised key

Mass in grams of copper deposited by passing 9.6487 A current through a voltmeter containing copper sulphate solution for 100 seconds is (Given : Molar mass of Cu : 63 g mol⁻¹, 1 F = 96487 C)

13.15 g

20.315 g

331.5 g

40.0315 g

NTA Answer: Option 2(revised_final)

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Lesson: Electrolytic Metallic Conduction

NEET 2023

The conductivity of centimolar solution of KCl at 25°C is 0.0210 ohm⁻¹ cm⁻¹ and the resistance of the cell containing the solution at 25°C is 60 ohm. The value of cell constant is

13.28 cm⁻¹

21.26 cm⁻¹

33.34 cm⁻¹

41.34 cm⁻¹

NTA Answer: Option 2(final)

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Lesson: Cell Potential Gibbs

NEET 2023

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A : In equation ΔᵣG = –nFE_cell, value of ΔᵣG depends on n. Reasons R : E_cell is an intensive property and ΔᵣG is an extensive property. In the light of the above statements, choose the correct answer from the options given below

1Both A and R are true and R is NOT the correct explanation of A

2A is true but R is false

3A is false but R is true

4Both A and R are true and R is the correct explanation of A

NTA Answer: Option 4(final)

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Lesson: Balancing Redox

NEET 2023

On balancing the given redox reaction, aCr₂O₇²⁻ + bSO₃²⁻(aq) + cH⁺(aq) → 2aCr³⁺(aq) + bSO₄²⁻(aq) + (c/2)H₂O(l) the coefficients a, b and c are found to be, respectively-

13, 8, 1

21, 8, 3

38, 1, 3

41, 3, 8

NTA Answer: Option 4(final)

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Lesson: Electrode Potential

NEET 2022

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 reaction cannot occur?

12CuSO4(aq) + 2Ag(s) → 2Cu(s) + Ag2SO4(aq)

2CuSO4(aq) + Zn(s) → ZnSO4(aq) + Cu(s)

3CuSO4(aq) + Fe(s) → FeSO4(aq) + Cu(s)

4FeSO4(aq) + Zn(s) → ZnSO4(aq) + Fe(s)

NTA Answer: Option 1(final)

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Lesson: EMF Galvanic

NEET 2022

Given below are half cell reactions: MnO₄⁻ + 8H⁺ + 5e⁻ → Mn²⁺ + 4H₂O, E°(Mn²⁺/MnO₄⁻) = −1.510 V; (1/2)O₂ + 2H⁺ + 2e⁻ → H₂O, E°(O₂/H₂O) = +1.223 V. Will the permanganate ion, MnO₄⁻ liberate O₂ from water in the presence of an acid?

1No, because E°cell = − 2.733 V

2Yes, because E°cell = + 0.287 V

3No, because E°cell = − 0.287 V

4Yes, because E°cell = + 2.733 V

NTA Answer: Option 2(final)

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Lesson: Oxidation Number

NEET 2022

Identify the incorrect statement from the following

1Lithium is the strongest reducing agent among the alkali metals.

2Alkali metals react with water to form their hydroxides.

3The oxidation number of K in KO2 is +4.

4Ionisation enthalpy of alkali metals decreases from top to bottom in the group.

NTA Answer: Option 3(final)

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NEET 2022

Find the emf of the cell in which the following reaction takes place at 298 K: Ni(s) + 2Ag⁺(0.001 M) → Ni²⁺(0.001 M) + 2Ag(s) (Given that E°cell = 10.5 V, 2.303 RT/F = 0.059 at 298 K)

11.05 V

21.0385 V

31.385 V

40.9615 V

NTA Answer: Option 5(final)

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Lesson: Kohlrausch Law

NEET 2021

The molar conductance of NaCl, HCl and CH COONa 3 at infinite dilution are 126.45, 426.16 and cm² mol⁻¹ 91.0 S respectively. The molar conductance of CH COOH at infinite dilution is. 3 Choose the right option for your answer. cm² mol⁻¹

1540.48 S cm² mol⁻¹

2201.28 S cm² mol⁻¹

3390.71 S cm² mol⁻¹

4698.28 S

NTA Answer: Option 3(final)

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Lesson: Oxidation Reduction Electronic

NEET 2021

Which of the following reactions is the metal displacement reaction? Choose the right option.

12Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂↑

22KClO₃ —[Δ]→ 2KCl + 3O₂

3Cr₂O₃ + 2Al —[Δ]→ Al₂O₃ + 2Cr

4Fe + 2HCl → FeCl₂ + H₂↑

NTA Answer: Option 3(final)

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Lesson: Molar Conductivity

NEET 2021

The molar conductivity of 0.007 M acetic acid is 20 S cm² mol⁻¹. What is the dissociation constant of acetic acid? Choose the correct option. [Λ°_H⁺ = 350 S cm² mol⁻¹; Λ°_CH₃COO⁻ = 50 S cm² mol⁻¹]

12.50 × 10⁻⁵ mol L⁻¹

21.75 × 10⁻⁴ mol L⁻¹

32.50 × 10⁻⁴ mol L⁻¹

41.75 × 10⁻⁵ mol L⁻¹

NTA Answer: Option 4(final)

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Lesson: Oxidation Number

NEET 2020

What is the change in oxidation number of carbon in the following reaction ? CH4 (g)+4Cl2 (g) → CCl4 (l)+4HCl(g)

10 to −4

2+4 to +4

30 to +4

4−4 to +4

NTA Answer: Option 4(final)

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Lesson: Electrochemical Cells

NEET 2020

The number of Faradays(F) required to produce 20 g of calcium from molten CaCl2 (Atomic mass of Ca=40 g mol⁻¹) is :

NTA Answer: Option 2(final)

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Lesson: Electrochemical Cells

NEET 2020

On electrolysis of dil.sulphuric acid using Platinum (Pt) electrode, the product obtained at anode will be :

1SO2 gas

2Hydrogen gas

3Oxygen gas

4H2S gas

NTA Answer: Option 3(final)

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Exam traps and common mistakes in this unit

Lesson: Nernst Equation

Trap

Nernst n electrons cumulative error

Category: Negative Marking

Multi-step Nernst problem: identify electrons, write Q correctly, plug into 0.0591/n. Each sub-step has factor errors.

When it triggers

Cell EMF problem at non-standard conditions.

How to avoid

Step-by-step: (1) write balanced redox; (2) count n electrons; (3) compute Q from concentrations; (4) plug into Nernst. Verify by checking limits: at standard conditions Q=1, log Q=0, E=E°.

Lesson: Nernst Equation

Trap

KMnO4 oxidation product depends on medium

Category: Inorganic Exception

Student assumes Mn²⁺ is the product regardless of medium. Acidic: → Mn²⁺ (5e⁻). Neutral/weakly basic: → MnO₂ (3e⁻). Strongly basic: → MnO₄²⁻ (1e⁻).

When it triggers

Question gives KMnO4 oxidation in unspecified or specific medium.

How to avoid

Always check medium. In acidic: Mn(+7) → Mn(+2). In neutral: → Mn(+4) (MnO₂). In basic: → Mn(+6) (manganate). The number of electrons (n) in Nernst calculations depends accordingly.

Lesson: Electrolytic Metallic Conduction

Mistake

Uses n=1 in Faraday's law for ions like Cu²⁺ (actual n=2) or Al³⁺ (n=3).

Root cause: concept gap

Correction

n = number of electrons per ion to deposit. Cu²⁺ + 2e⁻ → Cu: n=2. Al³⁺ + 3e⁻: n=3. m = MIt/(nF).

Lesson: Nernst Equation

Mistake

Uses incorrect electron count n in Nernst equation.

Root cause: formula misuse

Correction

n = electrons transferred per balanced redox equation. For Cu²⁺ + 2e⁻ → Cu: n=2. For Mn(VII) → Mn(II): n=5.

Formulas in this unit

Lesson: Cell Potential Gibbs

ΔG from EMF

Δ G = - n F E

Connection between thermodynamics and electrochemistry. F = 96485 C/mol.

Symbol	Quantity	SI Unit
ΔG	Gibbs energy change	J
n	electrons transferred	-
F	Faraday 96485	C/mol
E	cell EMF	V

Valid when

Single redox process

Lesson: Electrolytic Metallic Conduction

Faraday's law of electrolysis

m = \frac{M I t}{n F}

Mass deposited at electrode. M = molar mass; I = current; t = time; n = electrons per ion.

Symbol	Quantity	SI Unit
m	mass deposited	g
M	molar mass	g/mol
I	current	A
t	time	s
n	electrons per ion	-
F	Faraday	C/mol

Valid when

Steady current
Single product

Lesson: EMF Galvanic

Cell EMF

E_{cell}^{\circ} = E_{cath}^{\circ} - E_{anode}^{\circ}

Both as reduction potentials. E°_cell > 0 → spontaneous.

Symbol	Quantity	SI Unit
E°_cell	standard cell EMF	V
E°_red	reduction potential	V

Valid when

Standard conditions (1 M, 1 bar, 298 K)
Both half-reactions as reductions

Lesson: Molar Conductivity

Molar conductivity

Λ_{m} = \frac{1000 κ}{C}

Molar conductivity from specific conductance. Increases with dilution as more ions are free.

Symbol	Quantity	SI Unit
Λ_m	molar conductivity	S cm^2/mol
κ	specific conductance	S/cm
C	molarity	mol/L

Valid when

Aqueous solution
Single electrolyte

Lesson: Nernst Equation

Nernst equation

E = E^{\circ} - \frac{0.0591}{n} lo g Q

Cell potential at non-standard conditions. n = electrons transferred. At equilibrium E=0, Q=K.

Symbol	Quantity	SI Unit
E	cell potential	V
E°	standard	V
n	electrons	-
Q	reaction quotient	-

Valid when

298 K (else use RT/F)
Single redox process

NEET question patterns in this unit

Lesson: Kohlrausch Law

Compute Λ_m from κ and C. Or compute Λ°_m of weak electrolyte from strong electrolyte values via Kohlrausch.

Direct ApplicationMedium

Common distractors

inverts c multiplier

Uses Λ = κC instead of κ/C

forgets 1000 factor

Drops 1000 in unit conversion

Lesson: Nernst Equation

Apply Nernst equation to compute non-standard cell EMF given Q. n = electrons transferred.

Multi StepMedium

Common distractors

wrong n electrons

Uses incorrect electron count from half-reactions

Questions about this unit

What does Redox Reactions and Electrochemistry cover for NEET Chemistry?: 13 lessons: Balancing Redox, Cell Potential Gibbs, Dry Cell Lead Accumulator, Electrochemical Cells, Electrode Potential, Electrolytic Metallic Conduction, EMF Galvanic, Fuel Cells, Kohlrausch Law, Molar Conductivity, Nernst Equation, Oxidation Number and Oxidation Reduction Electronic.
How often has Redox Reactions and Electrochemistry come up in NEET past papers?: Our set of verified past papers has 21 questions from this unit, from NEET 2020, 2021, 2022, 2023, 2024, 2025 and 2026. Each is answered against the official NTA key.
Is the Redox Reactions and Electrochemistry material free?: Yes. All 13 lessons and 104 practice questions are free, with no login needed.