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Chemistry - Redox Reactions

Practise 107 JEE Main previous year questions on Redox Reactions, compiled from papers spanning 2002 to 2026. Each question is pulled directly from the actual exam paper it appeared in, so you're practising in the exact style and difficulty JEE Main tests.

Redox Reactions has been asked in 17 of the 25 years of JEE Main papers analysed (2002–2026), with 107 questions in all. 26% of them were easy, 62% moderate and 12% tough. Most of its questions came from 2021, with 21 questions that year. In the last three years (2024–2026) it had 26 questions across 49 papers, about 0.5 per paper.

The chapter's 6 topics are not weighted equally: Redox titration (36 questions, 34%), Oxidation and Reduction Reactions (17 questions, 16%), and Equivalence concept (16 questions, 15%) have been asked the most. Redox titration has also led over the last five years, with 23 questions. Redox titration has produced the most tough questions (7).

  1. 1mL of M MnO solution in basic medium when mixed with mL of M KI solution, oxidises iodide ions to liberate molecular iodine. This liberated 06 Apr, 2026 (E)Redox titration
  2. 2Given below are two statements: Statement I: Sodium dichromate and potassium dichromate are classified as primary standards in titrimetric a05 Apr, 2026 (M)Redox titration
  3. 3In order to oxidise a mixture of mole each of , , and in acidic medium, the number of moles of required is04 Apr, 2026 (M)Oxidation and Reduction Reactions
  4. 4500 mL of 1.2 M KI solution is mixed with 500 mL of solution in basic medium. The liberated iodine was titrated with standard solution in th28 Jan, 2026 (M)Redox titration
  5. 5X and Y are the number of electrons involved, respectively during the oxidation of to and to S by acidified . The value of is .24 Jan, 2026 (M)Balancing of redox reactions
  6. 6One mole of was passed into 2 L of cold 2 M KOH solution. After the reaction, the concentrations of and are respectively (assume volume rema24 Jan, 2026 (E)Types of redox reactions
  7. 7200 cc of potassium dichromate is required to oxidise 750 cc of 0.6 M Mohr's salt solution in acidic medium. Here .23 Jan, 2026 (E)Redox titration
  8. 8Identify the correct statements : A. Hydrated salts can be used as primary standard. B. Primary standard should not undergo any reaction wit22 Jan, 2026 (E)Equivalence concept
  9. 9Compounds that should not be used as primary standards in titrimetric analysis are : A. B. Oxalic acid C. NaOH D. E. Sodium tetraborate Choo03 Apr, 2025 (E)Redox titration
  10. 100.1 M solution of KI reacts with excess of and solutions. According to equation Identify the correct statements : (A) 200 mL of KI solution 29 Jan, 2025 (E)Equivalence concept
  11. 11Match the LIST-I with LIST-II Choose the correct answer from the options given below:28 Jan, 2025 (M)Types of redox reactions
  12. 12Given below are two statements: Statement I: In the oxalic acid vs (in the presence of dil ) titration the solution needs to be heated initi28 Jan, 2025 (M)Redox titration
  13. 13Some gas was kept in a sealed container at a pressure of 1 atm and at 273 K . This entire amount of gas was later passed through an aqueous 22 Jan, 2025 (M)Redox titration
  14. 14The species which does not undergo disproportionation reaction is :22 Jan, 2025 (E)Types of redox reactions
  15. 15Identify the incorrect statements regarding primary standard of titrimetric analysis. (A) It should be purely available in dry form. (B) It 09 Apr, 2024 (M)Redox titration
  16. 16Among the following halogens \( {F}_2, {Cl}_2, {Br}_2\) and \( {I}_2\) Which can undergo disproportionation reactions?08 Apr, 2024 (M)Types of redox reactions
  17. 17Thiosulphate reacts differently with iodine and bromine in the reactions given below: \( {aligned} & 2 {~S}_2 {O}_3^{2-}+ {I}_2 {S}_4 {O}_6^08 Apr, 2024 (M)Balancing of redox reactions
  18. 18Match List - I with List - II. \( {array}{ll} {List - I} & {List - II} \\ {Reaction} & {Type of redox reaction} \\ {(A) } {N}_{2( {~g})}+ {O06 Apr, 2024 (E)Types of redox reactions
  19. 19Only \(2 {~mL}\) of \( {KMnO}_4\) solution of unknown molarity is required to reach the end point of a titration of \(20 {~mL}\) of oxalic a04 Apr, 2024 (M)Redox titration
  20. 20Which of the following reactions are disproportionation reactions? 1 Cu + → Cu 2 + + Cu 2 3 MnO 4 2 - + 4 H + → 2 MnO 4 - + MnO 2 + 2 H 2 O 01 Feb, 2024 (M)Types of redox reactions
  21. 21In acidic medium, K 2 Cr 2 O 7 shows oxidising action as represented in the half reaction Cr 2 O 7 2 - + XH + + Ye - → 2 A + ZH 2 O X , Y , 01 Feb, 2024 (M)Balancing of redox reactions
  22. 22Given below are two statements : Statement (I) : Potassium hydrogen phthalate is a primary standard for standardisation of sodium hydroxide 01 Feb, 2024 (M)Redox titration
  23. 23Given below are two statements : Statement I: S 8 solid undergoes disproportionation reaction under alkaline conditions to form S 2 − and S 31 Jan, 2024 (E)Types of redox reactions
  24. 242 MnO 4 - + bI - + cH 2 O → xI 2 + yMnO 2 + zOH - If the above equation is balanced with integer coefficients, the value of z is ________.30 Jan, 2024 (M)Redox titration
  25. 25Total number of species from the following which can undergo disproportionation reaction ___________. H 2 O 2 , ClO 3 - , P 4 , Cl 2 , Ag , 30 Jan, 2024 (E)Types of redox reactions
  26. 26Chlorine undergoes disproportionation in alkaline medium as shown below : aCl 2 ( g ) + bOH - ( aq ) → cClO - ( aq ) + dCl - ( aq ) + eH 2 O29 Jan, 2024 (M)Balancing of redox reactions
  27. 27KMnO 4 decomposes on heating at 513 K to form O 2 along with29 Jan, 2024 (M)Redox titration
  28. 28If 50 mL of 0 . 5 M oxalic acid is required to neutralise 25 mL of NaOH solution, the amount of NaOH in 50 mL of given NaOH solution is_____29 Jan, 2024 (E)Redox titration
  29. 29Which of the following cannot function as an oxidising agent?27 Jan, 2024 (E)Oxidation and Reduction Reactions
  30. 30The total change in the oxidation state of manganese involved in the reaction of KMnO 4 and potassium iodide in the acidic medium is _______15 Apr, 2023 (M)Redox titration
  31. 31KMnO 4 is titrated with ferrous ammonium sulphate hexahydrate in presence of dilute H 2 SO 4 . Number of water molecules produced for 2 mole13 Apr, 2023 (M)Balancing of redox reactions
  32. 3220 mL of calcium hydroxide was consumed when it was reacted with 10 mL of unknown solution of H 2 SO 4 . Also 20 mL standard solution of 0 .13 Apr, 2023 (M)Equivalence concept
  33. 33See the following chemical reaction: Cr 2 O 7 2 - + XH + + 6 Fe 2 + YCr 3 + + 6 Fe 3 + + ZH 2 O The sum of X, Y and Z is13 Apr, 2023 (E)Balancing of redox reactions
  34. 34In alkaline medium, the reduction of permanganate anion involves a gain of ____________ electrons.10 Apr, 2023 (E)Redox titration
  35. 352 IO 3 - + xI - + 12 H + 6 I 2 + 6 H 2 What is the value of x ?08 Apr, 2023 (M)Balancing of redox reactions
  36. 36Given below are two statements: Statement I: In redox titration, the indicators used are sensitive to change in pH of the solution. Statemen08 Apr, 2023 (E)Redox titration
  37. 37Which of the following options are correct for the reaction? 2 Au ( CN ) 2 - ( aq ) + Zn ( s ) 2 Au ( s ) + Zn ( CN ) 4 2 - ( aq ) A. Redox 06 Apr, 2023 (M)Oxidation and Reduction Reactions
  38. 38Strong reducing and oxidizing agents among the following , respectively, are06 Apr, 2023 (M)Oxidation and Reduction Reactions
  39. 39During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3 . Identify which of the bel06 Apr, 2023 (E)Redox titration
  40. 40The volume of 0 . 02 M aqueous HBr required to neutralize 10 . 0 mL of 0 . 01 M aqueous Ba ( OH ) 2 is (Assume complete neutralization)06 Apr, 2023 (E)Equivalence concept
  41. 41Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : An aqueous solutio01 Feb, 2023 (E)Redox titration
  42. 42The density of a monobasic strong acid (Molar mass 24 . 2 g mol ) is 1 . 21 kg L . The volume of its solution required for the complete neut25 Jan, 2023 (M)Redox titration
  43. 43Choose the correct representation of conductometric titration of benzoic acid vs sodium hydroxide.24 Jan, 2023 (E)Redox titration
  44. 44A compound X is a weak acid and it exhibits colour change at pH close to the equivalence point during neutralization of NaOH with CH 3 COOH 29 Jul, 2022 (E)Redox titration
  45. 45Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R Assertion A : Permanganate titration ar28 Jul, 2022 (E)Balancing of redox reactions
  46. 4620 mL of 0 . 02 MK 2 Cr 2 O 7 solution is used for the titration of 10 mL of Fe 2 + solution in the acidic medium. The molarity of Fe 2 + so27 Jul, 2022 (M)Equivalence concept
  47. 47The normality of H 2 SO 4 in the solution obtained on mixing 100 mL of 0 . 1 M H 2 SO 4 with 50 mL of 0 . 1 M NaOH is____ 10 - 1 N .27 Jul, 2022 (E)Equivalence concept
  48. 48Which of the given reactions is not an example of disproportionation reaction?26 Jul, 2022 (M)Types of redox reactions
  49. 49Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R . Assertion A :Phenolphthalein is a pH 26 Jul, 2022 (E)Redox titration
  50. 5020 mL of 0 . 02 M hypo solution is used for the titration of 10 mL of copper sulphate solution, in the presence of excess of KI using starch26 Jul, 2022 (E)Redox titration

Frequently Asked Questions

1.How many questions are available for Redox Reactions?

This chapter includes 107 questions compiled from JEE Main papers spanning 2002 to 2026.

2.Are these questions only from JEE Main, or from other exams too?

These are JEE Main questions specifically for the Redox Reactions chapter. Questions from other exams like NTA Abhyas (JEE Main) or JEE Advanced are organised separately under their respective exam sections.

3.Is Redox Reactions an important chapter for JEE Main Chemistry?

Redox Reactions has appeared in 17 of the 25 years of JEE Main papers covered here, with 107 questions across 88 papers - about one per paper it appears in.

4.What is the difficulty level of Redox Reactions questions in JEE Main?

Of the 107 questions analysed for this chapter, 26% are easy, 62% moderate and 12% tough. 2021 had the most, with 21 questions.

5.Which topics in Redox Reactions should I focus on?

These topics have carried the most weightage in Redox Reactions:

  • Redox titration - 36 questions (34%)
  • Oxidation and Reduction Reactions - 17 questions (16%)
  • Equivalence concept - 16 questions (15%)
  • Redox titration has produced the most tough questions (7).
6.Is Redox Reactions's weightage in JEE Main going up or down?

Across all 88 papers analysed, Redox Reactions has averaged about 1.2 questions per paper. In the last three years (2024–2026), that average has fallen, at about 0.5 questions per paper. Use the year-wise numbers on this page for the exact trend before you decide how much time to give it.