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Friday, 9 October

JEE Main Chemistry · Class 12

Chemical Kinetics: JEE Main previous year questions

Chemical Kinetics had 48 questions in the 42 JEE Main shifts Lumi analysed, about 1.0 a shift, asked in 40 of 42 shifts. It ranks 12 of 30 Chemistry chapters by questions; 0% of its questions were hard.

Questions
48
in 40 of 42 shifts
A shift, on average
1.0
of 25 Chemistry questions
Since 2024
+0.4
0.8 a shift in 2017–23, 1.2 in 2024–26
Numerical answer
26
54% of its questions

Year by year

How often it came

Questions in the analysed shifts of each year. Years differ in how many shifts Lumi analysed, so read the bars with the shift count.

Questions each year
06121’173’204’215’223’239’2411’2512’26

2017: 1 shifts · 2020: 4 shifts · 2021: 4 shifts · 2022: 4 shifts · 2023: 4 shifts · 2024: 8 shifts · 2025: 8 shifts · 2026: 9 shifts

Difficulty by year
  • 20171
  • 20203
  • 20214
  • 20225
  • 20233
  • 20249
  • 202511
  • 202612
  • Easy
  • Medium
  • Hard

Inside the chapter

Topics and the ideas that repeat

4 topics and 26 distinct ideas; 11 ideas were asked more than once. Most questions are numerical value and calculation.

Topics, by questions

1 questions had no close topic in our taxonomy and are counted for the chapter only.

Ideas asked most
11 repeat

Study it on Lumi

Chemical Kinetics: the interactive lesson

Every question

All 48 Chemical Kinetics questions

Newest first. Each opens with its options and the official answer.

2026 12 questions

  1. 2 Apr 2026, Shift 1 · Q58t100%t_{100\%} is the time required for the 100%100\% completion of the reaction while t1/2t_{1/2} is the time required for 50%50\% of the…MediumSingle correct
  2. 2 Apr 2026, Shift 1 · Q74For reaction A→P\mathrm{A\rightarrow P}, rate constant k=1.5×103 s−1k=1.5\times10^3\ \mathrm{s^{-1}} at 27∘27^\circC If activation energy for the above…MediumNumerical value
  3. 2 Apr 2026, Shift 2 · Q57Consider the reaction aX→bYaX \to bY, for which the rate constant at 30°C is 1×10−31 \times 10^{-3} mol−1^{-1}Ls−1s^{-1}. Which of the following…MediumSingle correct
  4. 4 Apr 2026, Shift 1 · Q57Consider the first order reaction R→P\mathrm{R}\rightarrow\mathrm{P}. The fraction of molecules decomposed in the given first order…EasySingle correct
  5. 4 Apr 2026, Shift 2 · Q63Consider the given graph showing variation of reactant concentration with time. Three different reactions were started with identical…MediumSingle correctHas a figure
  6. 4 Apr 2026, Shift 2 · Q74For a first order reaction A→B\mathrm{A\rightarrow B} [table: t/min = 0, x, 20; [A]/M = 0.6500, 0.0650, 0.00065] x=x= ________ min.…MediumNumerical value
  7. 5 Apr 2026, Shift 1 · Q57First order gas phase reaction A→B+C\mathrm{A \rightarrow B + C} pip_i = initial pressure of gas A, ptp_t = total pressure of the reaction…MediumSingle correct
  8. 5 Apr 2026, Shift 1 · Q75If the half life of a first order reaction is 6.93 minutes then the time required for completion of 99% of the reaction will be ________…EasyNumerical value
  9. 5 Apr 2026, Shift 2 · Q75For a reaction A→P\mathrm{A\to P} at T K, the half life (t1/2t_{1/2}) is plotted as a function of initial concentration [A]0[\mathrm{A}]_0 of A…EasyNumerical valueHas a figure
  10. 6 Apr 2026, Shift 1 · Q74Sucrose hydrolyses in acidic medium into glucose and fructose by first order rate law with t1/2=3\mathrm{t_{1/2}}=3 hour. The percentage of…EasyNumerical value
  11. 6 Apr 2026, Shift 2 · Q75Decomposition of a hydrocarbon follows the equation k=(5.5×1011 s−1) e−28000 KTk=(5.5\times10^{11}\,\mathrm{s^{-1}})\,e^{\frac{-28000\,\mathrm{K}}{T}}. The…EasyNumerical value
  12. 8 Apr 2026, Shift 2 · Q57Given below are two statements : R=8.314 J K−1 mol−1R = 8.314\ \mathrm{J\,K^{-1}\,mol^{-1}} and 1 cal = 4.2 J Statement I : When Ea = 12.6 kcal/mol, the…MediumTwo statementsHas a figure

2025 11 questions

  1. 2 Apr 2025, Shift 1 · Q72For the reaction A →\rightarrow products. The concentration of A at 10 minutes is ___________ ×10−3\times10^{-3} mol L−1\mathrm{L^{-1}}…MediumNumerical valueHas a figure
  2. 2 Apr 2025, Shift 2 · Q56Reactant A converts to product D through the given mechanism (with the net evolution of heat) : A→BA \rightarrow B slow; ΔH=+\Delta H = +ve…MediumDiagram basedHas a figure
  3. 2 Apr 2025, Shift 2 · Q71For the reaction A→BA \rightarrow B the following graph was obtained. The time required (in seconds) for the concentration of A to reduce…MediumNumerical valueHas a figure
  4. 3 Apr 2025, Shift 1 · Q58In a reaction A+B→C\mathrm{A} + \mathrm{B} \rightarrow \mathrm{C}, initial concentrations of A and B are related as…MediumSingle correct
  5. 3 Apr 2025, Shift 2 · Q57Consider the following statements related to temperature dependence of rate constants. Identify the correct statements. A. The Arrhenius…MediumOther
  6. 4 Apr 2025, Shift 2 · Q54Half life of zero order reaction A→product\mathrm{A\rightarrow product} is 1 hour, when initial concentration of reactant is…EasySingle correct
  7. 4 Apr 2025, Shift 2 · Q55Consider the following plots of log of rate constant k (log k) vs 1T\frac{1}{T} for three different reactions. The correct order of…EasyDiagram basedHas a figure
  8. 7 Apr 2025, Shift 1 · Q56Reaction A(g)→2B(g)+C(g)\mathrm{A(g) \rightarrow 2B(g) + C(g)} is a first order reaction. It was started with pure A t/min | Pressure of system at time…MediumOtherHas a figure
  9. 7 Apr 2025, Shift 1 · Q57A person's wound was exposed to some bacteria and then bacterial growth started to happen at the same place. The wound was later treated…MediumDiagram basedHas a figure
  10. 7 Apr 2025, Shift 2 · Q57A(g)→B(g)+C(g)\mathrm{A(g)\to B(g)+C(g)} is a first order reaction. Time | tt | ∞\infty psystemp_{system} | ptp_t | p∞p_\infty The reaction was started…MediumSingle correct
  11. 8 Apr 2025, Shift 2 · Q54In a first order decomposition reaction, the time taken for the decomposition of reactant to one fourth and one eighth of its initial…EasySingle correct

2024 9 questions

  1. 6 Apr 2024, Shift 2 · Q85Consider the two different first order reactions given below A+B→CA + B \rightarrow C (Reaction 1) P→QP \rightarrow Q (Reaction 2) The ratio…MediumNumerical value
  2. 8 Apr 2024, Shift 1 · Q69Iron (III) catalyses the reaction between iodide and persulphate ions, in which A. Fe3+\mathrm{Fe^{3+}} oxidises the iodide ion B.…MediumOther
  3. 8 Apr 2024, Shift 1 · Q85Consider the following reaction A+B→C\mathrm{A + B \rightarrow C} The time taken for A to become 1/4th1/4^{\mathrm{th}} of its initial…MediumNumerical value
  4. 9 Apr 2024, Shift 1 · Q86Given below are two statements : Statement I : The rate law for the reaction A+B→C\mathrm{A + B \rightarrow C} is rate…EasyNumerical valueHas a figure
  5. 9 Apr 2024, Shift 2 · Q85Consider the following first order gas phase reaction at constant temperature A(g)→2B(g)+C(g)\mathrm{A(g) \rightarrow 2B(g) + C(g)} If the total…MediumNumerical value
  6. 29 Jan 2024, Shift 1 · Q87For a reaction taking place in three steps at same temperature, overall rate constant K=K1K2K3K=\frac{K_1K_2}{K_3}. If Ea1Ea_1, Ea2Ea_2 and Ea3Ea_3…MediumNumerical value
  7. 30 Jan 2024, Shift 2 · Q85NO2\mathrm{NO_2} required for a reaction is produced by decomposition of N2O5\mathrm{N_2O_5} in CCl4\mathrm{CCl_4} as by equation…EasyNumerical value
  8. 31 Jan 2024, Shift 1 · Q65Integrated rate law equation for a first order gas phase reaction is given by (where Pi\mathrm{P_i} is initial pressure and Pt\mathrm{P_t}…MediumSingle correct
  9. 31 Jan 2024, Shift 2 · Q85r = k [A] for a reaction, 50% of A is decomposed in 120 minutes. The time taken for 90% decomposition of A is _________ minutes.MediumNumerical value

2023 3 questions

  1. 8 Apr 2023, Shift 2 · Q63The correct reaction profile diagram for a positive catalyst reaction.EasyDiagram basedHas a figure
  2. 11 Apr 2023, Shift 1 · Q87KClO3+6FeSO4+3H2SO4→KCl+3Fe2(SO4)3+3H2O\mathrm{KClO_3 + 6FeSO_4 + 3H_2SO_4 \rightarrow KCl + 3Fe_2(SO_4)_3 + 3H_2O} The above reaction was studied at 300 K by monitoring the…MediumNumerical value
  3. 13 Apr 2023, Shift 2 · Q87A(g)→2B(g)+C(g)\mathrm{A(g)\rightarrow 2B(g)+C(g)} is a first order reaction. The initial pressure of the system was found to be 800 mm Hg which…MediumNumerical value

2022 5 questions

  1. 25 Jul 2022, Shift 1 · Q85The half life for the decomposition of gaseous compound A is 240240 s when the gaseous pressure was 500500 Torr initially. When the pressure…EasyNumerical value
  2. 28 Jul 2022, Shift 1 · Q80For kinetic study of the reaction of iodide ion with H2O2\mathrm{H_2O_2} at room temperature : (A) Always use freshly prepared starch…MediumOther
  3. 28 Jul 2022, Shift 1 · Q86For the given first order reaction A→B\mathrm{A\to B} the half life of the reaction is 0.3010 min. The ratio of the initial concentration…EasyNumerical value
  4. 24 Jun 2022, Shift 1 · Q85The rate constants for decomposition of acetaldehyde have been measured over the temperature range 700−1000700-1000 K. The data has been…EasyNumerical valueHas a figure
  5. 29 Jun 2022, Shift 1 · Q85The activation energy of one of the reactions in a biochemical process is 532611 J mol−1532611\ \mathrm{J\ mol^{-1}}. When the temperature falls from…MediumNumerical value

2021 4 questions

  1. 3 Aug 2021, Shift 2 · Q57The inactivation process of virus is first order with respect to virus concentration and 2% of the virus was inactivated in the first one…MediumNumerical value
  2. 25 Jul 2021, Shift 1 · Q31For the following graphs, (a) Rate vs Time: horizontal line (b) t1/2t_{1/2} vs Initial concentration: straight line through origin with…MediumDiagram basedHas a figure
  3. 16 Mar 2021, Shift 2 · Q58A and B decompose via first order kinetics with half-lives 54.0 min and 18.0 min respectively. Starting from an equimolar non reactive…MediumNumerical value
  4. 18 Mar 2021, Shift 1 · Q572 NO(g)+Cl2(g)⇌2 NOCl(s)\mathrm{2\,NO(g) + Cl_2(g) \rightleftharpoons 2\,NOCl(s)} This reaction was studied at −10-10°C and the following data was obtained run |…MediumNumerical value

2020 3 questions

  1. 8 Jan 2020, Shift 1 · Q27The rate of a certain biochemical reaction at physiological temperature (T) occurs 10610^6 times faster with enzyme than without. The…MediumSingle correct
  2. 9 Jan 2020, Shift 2 · Q48A sample of milk splits after 60 min. at 300 K and after 40 min. at 400 K when the population of lactobacillus acidophilus in it doubles.…MediumNumerical value
  3. 6 Sep 2020, Shift 2 · Q48The rate of a reaction decreased by 3.555 times when the temperature was changed from 40 °C to 30 °C. The activation energy (in kJ…MediumNumerical value

2017 1 questions

  1. 2 Apr 2017 (offline) · Q39Two reactions R1R_1 and R2R_2 have identical pre-exponential factors. Activation energy of R1R_1 exceeds that of R2R_2 by 10 kJ…EasySingle correct

Pattern: Asked most years.