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Chemistry - Chemical Kinetics

Practise 231 JEE Main previous year questions on Chemical Kinetics, 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.

Chemical Kinetics has been asked in 25 of the 25 years of JEE Main papers analysed (2002–2026), with 231 questions in all. 30% of them were easy, 55% moderate and 15% tough. Most of its questions came from 2021, with 26 questions that year. In the last three years (2024–2026) it had 57 questions across 49 papers, about 1.2 per paper.

The chapter's 6 topics are not weighted equally: Integrated rate laws (79 questions, 34%), Arrhenius theory (58 questions, 25%), and Rate law and rate constant (41 questions, 18%) have been asked the most. Integrated rate laws has also led over the last five years, with 43 questions. Arrhenius theory has produced the most tough questions (11).

  1. 1Given below are two statements: J K mol and cal J Statement I: When kcal/mol, the room temperature rate constant is doubled by a C increase 08 Apr, 2026 (E)Arrhenius theory
  2. 2Decomposition of a hydrocarbon follows the equation . The activation energy of reaction is __________ kJ mol . (Nearest Integer) Given : R J06 Apr, 2026 (E)Arrhenius theory
  3. 3First order gas phase reaction initial pressure of gas A, total pressure of the reaction mixture at time Expression of rate constant ( ) is05 Apr, 2026 (M)Integrated rate laws
  4. 4If the half life of a first order reaction is minutes then the time required for completion of % of the reaction will be _____ minutes. (Giv05 Apr, 2026 (M)Integrated rate laws
  5. 5For a reaction at , the half life is plotted as a function of initial concentration of as given below. The value of in the given figure is _05 Apr, 2026 (E)Integrated rate laws
  6. 6Consider the first order reaction . The fraction of molecules decomposed in the given first order reaction can be expressed as04 Apr, 2026 (M)Integrated rate laws
  7. 7Consider the given graph showing variation of reactant concentration with time. Three different reactions were started with identical initia04 Apr, 2026 (E)Rate of reaction
  8. 8For a first order reaction ______ min. (Nearest integer)04 Apr, 2026 (E)Integrated rate laws
  9. 9is the time required for the completion of the reaction while is the time required for of the reaction to be completed. Which of the followi02 Apr, 2026 (M)Integrated rate laws
  10. 10For reaction , rate constant s at C. If activation energy for the above reaction is kJ mol , then the temperature (in C) at which rate const02 Apr, 2026 (M)Arrhenius theory
  11. 11Consider the reaction , for which the rate constant at is mol L s . Which of the following statements are true? A. When concentration of 'X'02 Apr, 2026 (E)Rate law and rate constant
  12. 12Consider the following gas phase reaction being carried out in a closed vessel at . time (min) total pressure of the system (mm Hg) The pres02 Apr, 2026 (E)Rate of reaction
  13. 13An organic compound undergoes first order decomposition. The time taken for decomposition to and of its initial concentration are and respec28 Jan, 2026 (M)Integrated rate laws
  14. 14(first reaction) (second reaction) Consider the above two first-order reactions. The rate constant for first reaction at 500 K is double of 28 Jan, 2026 (E)Arrhenius theory
  15. 15At in presence of a catalyst, activation energy of a reaction is lowered by . The logarithm of ratio of is.... (Consider that the frequency 24 Jan, 2026 (M)Arrhenius theory
  16. 16The half-life of is 245 days. After days, of original activity remained. The value of in days is . (Nearest integer) (Given: and )24 Jan, 2026 (E)Integrated rate laws
  17. 17For the thermal decomposition of reactant , the following plot is constructed. The half life of the reaction is ' . min. (Nearest integer)23 Jan, 2026 (M)Integrated rate laws
  18. 18Given above is the concentration vs time plot for a dissociation reaction : . Based on the data of the initial phase of the reaction (initia23 Jan, 2026 (E)Rate of reaction
  19. 19Observe the following reactions at . I. products. II. Both the reactions are started at 10.00 am. The rates of these reactions at 10.10 am a23 Jan, 2026 (E)Rate law and rate constant
  20. 20product (First order reaction). Three sets of experiment were performed for a reaction under similar experimental conditions: Run of 10 M so22 Jan, 2026 (M)Rate law and rate constant
  21. 21The temperature at which the rate constants of the given below two gaseous reactions become equal is K. (Nearest integer) Given:22 Jan, 2026 (M)Arrhenius theory
  22. 22Correct statements regarding Arrhenius equation among the following are : A. Factor corresponds to fraction of molecules having kinetic ener22 Jan, 2026 (E)Arrhenius theory
  23. 23Consider and are two reactions. If the rate constant of the reaction can be expressed by the following equation and activation energy of rea22 Jan, 2026 (E)Arrhenius theory
  24. 24Pre-exponential factors of two different reactions of same order are identical. Let activation energy of first reaction exceeds the activati21 Jan, 2026 (M)Arrhenius theory
  25. 25Decomposition of A is a first order reaction at and is given by . In a closed 1 L vessel, 1 bar is allowed to decompose at . After 100 minut21 Jan, 2026 (E)Integrated rate laws
  26. 26In a first order decomposition reaction, the time taken for the decomposition of reactant to one fourth and one eighth of its initial concen08 Apr, 2025 (E)Integrated rate laws
  27. 27Reaction is a first order reaction. It was started with pure A Which of the following option is incorrect ?07 Apr, 2025 (M)Rate law and rate constant
  28. 28A person's wound was exposed to some bacteria and then bacteria growth started to happen at the same place. The wound was later treated with07 Apr, 2025 (M)Integrated rate laws
  29. 29is a first order reaction. The reaction was started with reactant A only. Which of the following expression is correct for rate constant k ?07 Apr, 2025 (E)Rate law and rate constant
  30. 30Rate law for a reaction between A and B is given by If concentration of A is doubled and concentration of is halved from their initial value04 Apr, 2025 (M)Rate law and rate constant
  31. 31For for forward and backward reaction are 180 and respectively If catalyst lowers for both reaction by . Which of the following statement is04 Apr, 2025 (M)Arrhenius theory
  32. 32Half life of zero order reaction product is 1 hour, when initial concentration of reaction is . The time required to decrease concentration 04 Apr, 2025 (E)Integrated rate laws
  33. 33Consider the following plots of log of rate constant vs for three different reactions. The correct order of activation energies of these rea04 Apr, 2025 (E)Arrhenius theory
  34. 34In a reaction , initial concentrations of and are related as . The half lives of and are 10 min and 40 min. respectively. If they start to d03 Apr, 2025 (M)Integrated rate laws
  35. 35Consider the following statements related to temperature dependence of rate constants. Identify the correct statements, A. The Arrhenius equ03 Apr, 2025 (E)Arrhenius theory
  36. 36For the reaction \( {A} \) products. The concentration of A at 10 minutes is _______ \( 10^{-3} {~mol} {~L}^{-1}\) (nearest integer). The re02 Apr, 2025 (M)Integrated rate laws
  37. 37For the reaction the following graph was obtained. The time required (in seconds) for the concentration of A to reduce to (if the initial co02 Apr, 2025 (E)Rate law and rate constant
  38. 38Reactant A converts to product D through the given mechanism (with the net evolution of heat) : slow fast; fast ; Which of the following rep02 Apr, 2025 (E)Arrhenius theory
  39. 39The reaction \( {A}_2+ {B}_2 2 {AB}\) follows the mechanism The overall order of the reaction is :29 Jan, 2025 (M)Methods to determine order of reaction
  40. 40Drug becomes ineffective after decomposition. The original concentration of drug in a bottle was which becomes in 12 months. The expiry time29 Jan, 2025 (E)Integrated rate laws
  41. 41For a given reaction is related to as given in table. Given: Which of the following is true? A. The order of the reaction is . B. If is 1 M 28 Jan, 2025 (M)Integrated rate laws
  42. 42For bacterial growth in a cell culture, growth law is very similar to the law of radioactive decay. Which of the following graphs is most su28 Jan, 2025 (E)Integrated rate laws
  43. 43Consider an elementary reaction If the volume of reaction mixture is suddenly reduced to of its initial volume, the reaction rate will becom28 Jan, 2025 (E)Rate law and rate constant
  44. 44Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :24 Jan, 2025 (E)Methods to determine order of reaction
  45. 45Consider a complex reaction taking place in three steps with rate constants and respectively. The overall rate constant is given by the expr24 Jan, 2025 (E)Arrhenius theory
  46. 46For the thermal decomposition of at constant volume, the following table can be formed, for the reaction mentioned below. Given : Rate const23 Jan, 2025 (M)Integrated rate laws
  47. 47Which of the following graphs most appropriately represents a zero order reaction ?23 Jan, 2025 (E)Rate law and rate constant
  48. 48Which of the following statement is not true for radioactive decay?22 Jan, 2025 (M)Integrated rate laws
  49. 49The molecule A changes into its isomeric form B by following a first order kinetics at a temperature of 1000 K . If the energy barrier with 22 Jan, 2025 (M)Integrated rate laws
  50. 50Consider the given figure and choose the correct option :22 Jan, 2025 (E)Arrhenius theory

Frequently Asked Questions

1.How many questions are available for Chemical Kinetics?

This chapter includes 231 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 Chemical Kinetics chapter. Questions from other exams like NTA Abhyas (JEE Main) or JEE Advanced are organised separately under their respective exam sections.

3.Is Chemical Kinetics an important chapter for JEE Main Chemistry?

Chemical Kinetics has appeared in 25 of the 25 years of JEE Main papers covered here, with 231 questions across 195 papers - about one per paper it appears in.

4.What is the difficulty level of Chemical Kinetics questions in JEE Main?

Of the 231 questions analysed for this chapter, 30% are easy, 55% moderate and 15% tough. 2021 had the most, with 26 questions.

5.Which topics in Chemical Kinetics should I focus on?

These topics have carried the most weightage in Chemical Kinetics:

  • Integrated rate laws - 79 questions (34%)
  • Arrhenius theory - 58 questions (25%)
  • Rate law and rate constant - 41 questions (18%)
  • Arrhenius theory has produced the most tough questions (11).
6.Is Chemical Kinetics's weightage in JEE Main going up or down?

Across all 195 papers analysed, Chemical Kinetics has averaged about 1.2 questions per paper. In the last three years (2024–2026), that average has stayed about the same, at about 1.2 questions per paper. Use the year-wise numbers on this page for the exact trend before you decide how much time to give it.