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Chemical Equilibrium JEE Main PYQs, 2020 to 2025

Chemical Equilibrium has 52 questions in JEE Main papers from 2020 to 2025, about 8.7 per year across all shifts. The most asked topic is Law of Mass Action (42 questions), followed by Le Chatelier's Principle (8) and Kc and Kp (2).

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52Total PYQs
6Years covered
3Topics
2025 Apr S1Latest paper

Chemical Equilibrium questions per year

YearQuestions
20256
202412
202311
20224
202113
20206

Topic-wise weightage

TopicQuestionsShare of chapterLast asked
Law of Mass Action4281%2025
Le Chatelier's Principle815%2025
Kc and Kp24%2024

Sample questions from recent papers

JEE Main 2025 · 3 Apr · Shift 1 · Law of Mass Action

Given below are two statements :

Statement I : A catalyst cannot alter the equilibrium constant (Kc)({\mathrm{K}}_{{{\mathrm{c}}}}) of the reaction, temperature remaining constant.

Statement II : A homogenous catalyst can change the equilibrium composition of a system, temperature remaining constant.

In the light of the above statements, choose the correct answer from the options given below

  1. (A) Statement I is true but Statement II is false
  2. (B)Statement I is false but Statement II is true
  3. (C) Both Statement I and Statement II are true
  4. (D)Both Statement I and Statement II are false
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Answer: (A)

Step-by-step solution

JEE Main 2025 · 3 Apr · Shift 1 · Le Chatelier's Principle

In the following system, PCl5( g)⇋PCl3( g)+Cl2( g){\mathrm{PCl}}_{5}({\ \mathrm{g}})\leftrightharpoons {\mathrm{PCl}}_{3}({\ \mathrm{g}})+{\mathrm{Cl}}_{2}({\ \mathrm{g}}) at equilibrium, upon addition of xenon gas at constant T \& p , the concentration of
  1. (A)PCl5,PCl3&Cl2{\mathrm{PCl}}_{5},{\mathrm{PCl}}_{3}\&{\mathrm{Cl}}_{2} remain constant
  2. (B)PCl3{\mathrm{PCl}}_{3} will increase
  3. (C) Cl2{\mathrm{Cl}}_{2} will decrease
  4. (D) PCl5{\mathrm{PCl}}_{5} will increase
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Answer: (B)

Step-by-step solution

JEE Main 2024 · 31 Jan · Shift 1 · Kc and Kp

Consider the following reaction at 298 K⋅32O2(g)⇌O3(g)⋅KP=2.47×10−29298 \mathrm{~K} \cdot \frac{3}{2} \mathrm{O}_{2(g)} \rightleftharpoons \mathrm{O}_{3(g)} \cdot \mathrm{K}_{\mathrm{P}}=2.47 \times 10^{-29}. ΔrG⊖\Delta_r G^{\ominus} for the reaction is _________ kJ\mathrm{kJ}. (Given R=8.314 JK−1 mol−1\mathrm{R}=8.314 \mathrm{~JK}^{-1} \mathrm{~mol}^{-1})

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Answer: 163

Step-by-step solution

All 52 questions are in the free PDF above, grouped by topic.

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Frequently asked

How many questions come from Chemical Equilibrium in JEE Main?

52 questions from 2020 to 2025, about 8.7 per year. In 2025 it had 6.

Which Chemical Equilibrium topics are most important for JEE Main?

By past papers: Law of Mass Action (81%), Le Chatelier's Principle (15%) and Kc and Kp (4%) of all Chemical Equilibrium questions.

Is the Chemical Equilibrium PYQ PDF free?

Yes. The PDF, the answer key and every step-by-step solution on PrepWiser are free, with no login needed to practise.

More Chemistry chapters

JEE Main PYQs by year: 2025 · 2024 · 2023 · 2022 · 2021 · 2020 · 2019

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