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Sunday, 25 October

JEE Main · Chemistry · Class 11

Redox Reactions: JEE Main previous year questions

49 questions in 40 of the 108 JEE Main shifts Lumi analysed, asked in 6 of 8 years. Here is what this chapter tests and how.

Study this chapter
Questions
49
in 40 of 108 shifts · 6 of 8 years
Average a shift
0.3
of 25 Chemistry · 0.3 since 2024 0.0
Typical range
0.0–0.6
questions a shift; fewest 0.0, most 0.7
Weighted estimate
0.4
model, recent years count more · about 1.5 marks
  • Typical range (fact)
  • Average a shift (fact)
  • Weighted estimate (model)

Questions are counted per shift, out of the 25 each subject has, in the shifts Lumi analysed; papers that offered 30 a subject (2017, 2021–2024) are scaled to 25. Typical range: the middle six of the eight years (2017, 2020–2026), leaving out the single highest and lowest year. The average and the range are historical fact. The weighted estimate is a model: each year's share, with recent years counting more (half-life three years), and chapters NTA dropped from the syllabus set near zero. It is a guide to effort, not a forecast of the paper.

What to do

How to spend time on Redox Reactions

Priority

Lower priority

One of the 6 Chemistry chapters that shared the last fifth of Chemistry questions in the 108 shifts analysed. How bands are set

Past questions
49in 40 of 108 shifts
Study plan gives it
7 hover 12 months; 6 h over 6
Study this chapter →

Ideas asked most often

  1. Oxidation Number Assignment9×
  2. Disproportionation Balancing7×
  3. Law of Chemical Equivalence in Redox6×
  4. Permanganate n-Factor Across Media6×
  5. Ion-Electron Acidic4×

26 of the 50 ideas in Lumi’s map of this chapter have not been asked or touched in the shifts analysed. Of its idea-tagged questions from 2024 on, 19% tested an idea not asked in an earlier year, so learn the whole chapter, not just the list above.

Within each subject, chapters in NTA's 2026 syllabus are ranked by their average questions a shift over all 8 years analysed (history, not the model). Going down that list, the chapters that together held the first half of the subject's questions are Must do; the next ones, up to 80%, are Should do; the rest are Lower priority.

Key findings

Redox Reactions at a glance

  1. 01

    81%

    of its 16 questions from 2024 on that Lumi matched to an idea tested one JEE Main had asked in an earlier year; 100% came from a topic asked in an earlier year.

  2. 02

    52%

    of the 50 ideas in Lumi's map of the chapter have not been asked or touched on in the shifts analysed.

  3. 03

    53%

    of its questions asked for a numerical answer, 1.8 times the Chemistry average.

  4. 04

    2%

    of its questions were rated hard, against 6% across all Chemistry questions in the same shifts.

Questions a shift, year by year

Out of the 25 Chemistry questions in a shift. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift.

0240’170.3’200.3’210.3’220.7’230.6’240’250.3’26

Raw count: 2017: 0 in 1 shift · 2020: 4 in 12 shifts · 2021: 9 in 24 shifts · 2022: 9 in 24 shifts · 2023: 10 in 12 shifts · 2024: 14 in 18 shifts · 2025: 0 in 8 shifts · 2026: 3 in 9 shifts.

Kind of question

SHARE OF QUESTIONS
  • Numerical answer53%
  • Conceptual18%
  • Application10%
  • Calculation8%
  • Two statements6%
  • Multi-step2%
  • Match the list2%

Most common asks: molarity from redox titration (2); identify set of species reducing dichromate (1); moles of oxidant for mixture (1).

Profile

This chapter in numbers

Where it ranks, how steady it is, and what it costs to study.

Rank, all JEE chapters
#68
of 70 by weighted estimate
Rank in Chemistry
#20
of 21 chapters
Share of Chemistry
1.3%
of its questions, all shifts analysed
Busiest year
2023
0.7 questions a shift
Year to year
Swings a lot
varies by about 0.2 questions a shift
Long-run direction
+0.03
questions a shift, per year
Easy questions
47%
2% rated hard
Numerical answer
53%
1.8× the Chemistry rate
With a figure
0%
graph, diagram or structure
Study time
7 h
6 h on a 6-month plan
Marks per study hour
0.21
#64 of 70 chapters
Foundation for others
40%
of its ideas are used in other chapters

Difficulty, year by year

Each question rated easy, medium or hard. Each bar is that year’s split, so years compare directly; the number is the questions in that year’s analysed shifts (1 to 24 shifts a year).

  • 2017
  • 20204
  • 20219
  • 20229
  • 202310
  • 202414
  • 2025
  • 20263
  • Easy
  • Medium
  • Hard

What it asks you to do

SHARE OF QUESTIONS
  • Calculation45%
  • Conceptual27%
  • Application16%
  • Multi-step6%
  • Recall6%

Coverage

How much of the chapter JEE Main has used

We split the chapter into 50 ideas. In the 108 shifts analysed, JEE Main built a question around 16 of them. Most of the chapter has never been the main idea of a question, so past questions alone leave most of it out.

Asked as the main idea
16
Touched on in a question
8
Never asked
26

Topics

What repeats, topic by topic

This chapter's questions per topic in each year's analysed shifts. The number is the count; the shade is scaled to one shift, so a year with more analysed shifts (1 to 24 a year) does not look darker. 2 questions had no close topic in Lumi's map and count for the chapter only.

’17’20’21’22’23’24’25’26
012+questions in that year’s analysed shifts, shaded per shift
  • Redox Reactions

    As a topic: 50 questions in 7 of 8 years, most often numerical value, 54% numerical answer.

  • Hydrogen and Hydrides

    As a topic: 62 questions in 4 of 8 years, most often single correct, 8% numerical answer.

  • Anion Analysis

    As a topic: 19 questions in 7 of 8 years, most often single correct, 5% numerical answer.

Drill down

Topic, idea, question

Open a topic to see every idea JEE Main tested inside it, then open an idea to read the questions. Each row shows its 8 years.

  • Open44 · 90%4889123

    13 ideas inside

    • OpenRepeated9 · 20%3222
    • OpenRepeated7 · 16%24
    • OpenRepeated6 · 14%2
    • OpenRepeated6 · 14%4
    • OpenRepeated4 · 9%22
    • OpenRepeated3 · 7%
    • OpenRepeated2 · 5%
    • Open2 · 5%2
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
    • Open1 · 2%
  • Open2 · 4%
  • Open1 · 2%
  • 1 Feb ’24 S1 · Q84
    The lowest oxidation number of an atom in a compound A2B\mathrm{A_2B} is −2-2. The number of electrons in its valence shell is ________.

    easyNumerical value

  • 8 Apr ’23 S2 · Q80
    Given below are two statements: Statement I : In redox titration, the indicators used are sensitive to change in pH of the solution.…

    easyTwo statements

Squares are the 8 years with analysed shifts, 2017 to 2026. A number is the questions that year when there is more than one; the shade is scaled to one shift, so a year with more analysed shifts (1 to 24 a year) does not look darker. Share is of the level above.

Ideas

The exact ideas JEE Main has asked

Inside the topics, 13 different ideas were tested; 9 came more than once. These are the repeats, then the ideas new since 2024.

Dots are the 8 years with analysed shifts, 2017 to 2026.

Every question

All 49 Redox Reactions questions

Newest first, shift by shift. The newest 40 show their opening words; older ones name the idea they tested. Each opens with its options and the official answer.

JEE Main 20263 questions

  1. 2 Apr 2026, Shift 1 · Q61Which of the following sets includes all the species that will change the orange colour of K2Cr2O7\mathrm{K_2Cr_2O_7} in acidic medium ?MediumSingle correct
  2. 4 Apr 2026, Shift 1 · Q56In order to oxidise a mixture of 11 mole each of FeC2O4\mathrm{FeC_2O_4}, Fe2(C2O4)3\mathrm{Fe_2(C_2O_4)_3}, FeSO4\mathrm{FeSO_4} and…MediumSingle correct
  3. 6 Apr 2026, Shift 2 · Q73500 mL of 0.2 M MnO4−\mathrm{MnO_4^-} solution in basic medium when mixed with 500 mL of 1.5 M KI solution, oxidises iodide ions to liberate…MediumNumerical value

JEE Main 202414 questions

  1. 4 Apr 2024, Shift 1 · Q87Only 2 mL of KMnO4\mathrm{KMnO_4} solution of unknown molarity is required to reach the end point of a titration of 20 mL of oxalic acid (2…MediumNumerical value
  2. 6 Apr 2024, Shift 2 · Q64Match List - I with List - II. List - I (Reaction) (A) N2(g)+O2(g)→2NO(g)\mathrm{N_{2(g)}+O_{2(g)}\rightarrow 2NO_{(g)}} (B)…EasyMatch the list
  3. 8 Apr 2024, Shift 1 · Q64Thiosulphate reacts differently with iodine and bromine in the reactions given below:…MediumSingle correct
  4. 9 Apr 2024, Shift 1 · Q65Given below are two statements : Statement (I) : The oxidation state of an element in a particular compound is the charge acquired by its…MediumTwo statements
  5. 1 Feb 2024, Shift 1 · Q67In acidic medium, K2Cr2O7\mathrm{K_2Cr_2O_7} shows oxidising action as represented in the half reaction :…EasySingle correct
  6. 1 Feb 2024, Shift 1 · Q68Which of the following reactions are disproportionation reactions ? (A) Cu+→Cu2++Cu\mathrm{Cu^+ \rightarrow Cu^{2+} + Cu} (B)…MediumOther
  7. 1 Feb 2024, Shift 1 · Q84The lowest oxidation number of an atom in a compound A2B\mathrm{A_2B} is −2-2. The number of electrons in its valence shell is ________.EasyNumerical value
  8. 27 Jan 2024, Shift 1 · Q85From the given list, the number of compounds with +4 oxidation state of Sulphur is __________.…EasyNumerical value
  9. 29 Jan 2024, Shift 1 · Q63Chlorine undergoes disproportionation in alkaline medium as shown below :…EasySingle correct
  10. 29 Jan 2024, Shift 1 · Q79In chromyl chloride test for confirmation of Cl−\mathrm{Cl^-} ion, a yellow solution is obtained. Acidification of the solution and…MediumSingle correct
  11. 30 Jan 2024, Shift 1 · Q852MnO4−+bI−+cH2O→x I2+y MnO2+z O‾H\mathrm{2MnO_4^- + bI^- + cH_2O \rightarrow x\,I_2 + y\,MnO_2 + z\,\overline{O}H} If the above equation is balanced with integer…MediumNumerical value
  12. 30 Jan 2024, Shift 2 · Q84Total number of species from the following which can undergo disproportionation reaction is ________.…MediumNumerical value
  13. 31 Jan 2024, Shift 2 · Q65Given below are two statements : Statement I : S8\mathrm{S_8} solid undergoes disproportionation reaction under alkaline conditions to…MediumTwo statements
  14. 31 Jan 2024, Shift 2 · Q86Number of moles of H+\mathrm{H^+} ions required by 1 mole of MnO4−\mathrm{MnO_4^-} to oxidise oxalate ion to CO2\mathrm{CO_2} is ________.MediumNumerical value

JEE Main 202310 questions

  1. 6 Apr 2023, Shift 1 · Q65Which of the following options are correct for the reaction…MediumOther
  2. 6 Apr 2023, Shift 1 · Q90In ammonium – phosphomolybdate, the oxidation state of Mo is + ________MediumNumerical value
  3. 6 Apr 2023, Shift 2 · Q69During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the…MediumSingle correct
  4. 8 Apr 2023, Shift 1 · Q612IO3−+xI−+12H+→6I2+6H2O2\mathrm{IO_3^-} + x\mathrm{I^-} + 12\mathrm{H^+} \rightarrow 6\mathrm{I_2} + 6\mathrm{H_2O} What is the value of xx?EasySingle correct
  5. 8 Apr 2023, Shift 2 · Q80Given below are two statements: Statement I : In redox titration, the indicators used are sensitive to change in pH of the solution.…EasyTwo statements
  6. 10 Apr 2023, Shift 2 · Q90In alkaline medium, the reduction of permanganate anion involves a gain of ____________ electrons.EasyNumerical value
  7. 13 Apr 2023, Shift 1 · Q81KMnO4\mathrm{KMnO_4} is titrated with ferrous ammonium sulphate hexahydrate in presence of dilute H2SO4\mathrm{H_2SO_4}. Number of water…EasyNumerical value
  8. 13 Apr 2023, Shift 2 · Q88See the following chemical reaction:…EasyNumerical value
  9. 15 Apr 2023, Shift 1 · Q88The total change in the oxidation state of manganese involved in the reaction of KMnO4\mathrm{KMnO_4} and potassium iodide in the acidic…EasyNumerical value
  10. 15 Apr 2023, Shift 1 · Q90In Chromyl chloride, the oxidation state of chromium is (+) __________.EasyNumerical value

JEE Main 20229 questions

  1. 26 Jul 2022, Shift 1 · Q68Which of the given reactions is not an example of disproportionation reaction ?EasySingle correct
  2. 26 Jul 2022, Shift 1 · Q69The dark purple colour of KMnO4\mathrm{KMnO_4} disappears in the titration with oxalic acid in acidic medium. The overall change in the…EasySingle correct
  3. 26 Jul 2022, Shift 2 · Q8520 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 starch…MediumNumerical value
  4. 27 Jul 2022, Shift 1 · Q8120 mL of 0.02 M K2Cr2O7\mathrm{K_2Cr_2O_7} solution is used for the titration of 10 mL of Fe2+\mathrm{Fe^{2+}} solution in the acidic medium. The…EasyNumerical value
  5. 27 Jul 2022, Shift 1 · Q88In the titration of KMnO4\mathrm{KMnO_4} and oxalic acid in acidic medium, the change in oxidation number of carbon at the end point is _____EasyNumerical value
  6. 28 Jul 2022, Shift 2 · Q57On reaction with stronger oxidizing agent like KIO4\mathrm{KIO_4}, hydrogen peroxide oxidizes with the evolution of O2\mathrm{O_2}. The…EasyNumerical value
  7. 24 Jun 2022, Shift 1 · Q86The difference in oxidation state of chromium in chromate and dichromate salts is ______.EasyNumerical value
  8. 26 Jun 2022, Shift 2 · Q68Which one of the following is an example of disproportionation reaction ?MediumSingle correct
  9. 28 Jun 2022, Shift 2 · Q900.01 M KMnO4\mathrm{KMnO_4} solution was added to 20.0 mL of 0.05 M Mohr’s salt solution through a burette. The initial reading of 50 mL…MediumNumerical value

JEE Main 20219 questions

  1. 27 Aug 2021, Shift 1 · Q39In polythionic acid, H2SxO6\mathrm{H_2S_xO_6} (xx = 3 to 5) the oxidation state(s) of sulphur is/are :MediumSingle correct
  2. 31 Aug 2021, Shift 2 · Q38In which one of the following sets all species show disproportionation reaction ?MediumSingle correct
  3. 24 Feb 2021, Shift 1 · Q35(A) HOCl+H2O2→H3O++Cl−+O2\mathrm{HOCl + H_2O_2 \rightarrow H_3O^+ + Cl^- + O_2} (B) I2+H2O2+2OH−→2I−+2H2O+O2\mathrm{I_2 + H_2O_2 + 2OH^- \rightarrow 2I^- + 2H_2O + O_2} Choose the…EasySingle correct
  4. 24 Feb 2021, Shift 1 · Q57The reaction of sulphur in alkaline medium is given below :…MediumNumerical value
  5. 25 Feb 2021, Shift 1 · Q55Law of Chemical Equivalence in Redox · Medium · Numerical value
  6. 26 Feb 2021, Shift 2 · Q59Permanganate n-Factor Across Media · Hard · Numerical value
  7. 25 Jul 2021, Shift 2 · Q32Oxidation Number Assignment · Easy · Single correct
  8. 17 Mar 2021, Shift 1 · Q57Law of Chemical Equivalence in Redox · Medium · Numerical value
  9. 18 Mar 2021, Shift 2 · Q38Oxidation Number Assignment · Easy · Single correct

JEE Main 20204 questions

  1. 9 Jan 2020, Shift 1 · Q35Identifying Redox Agents · Easy · Single correct
  2. 2 Sep 2020, Shift 2 · Q49Oxidation State Method · Easy · Numerical value
  3. 4 Sep 2020, Shift 1 · Q49Law of Chemical Equivalence in Redox · Medium · Numerical value
  4. 4 Sep 2020, Shift 2 · Q49Oxidation State Method · Medium · Numerical value

Questions from the official JEE Main papers published by NTA. Chapter, topic and idea tags, counts and notes are Lumi’s. Pattern: Asked most years.

More Chemistry, Class 11

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