Chemical Equilibrium — JEE Main PYQs & Practice Questions

Chemical Equilibrium is a Chemistry chapter in the JEE Main syllabus. This page brings together 81 previous-year and practice questions on Chemical Equilibrium, organised into 3 topics: Law of Mass Action, Kc and Kp and Le Chatelier's Principle. Most questions come with a step-by-step solution you can work through free in PrepWiser.

Download Chemical Equilibrium JEE Main PYQs as a free PDF (with answer key)

Revise this chapter: Revision notes · Formula sheet

Chapter weightage: how many questions each chapter had per shift in the 2024–26 papers.

Law of Mass Action

• The equilibrium constant for the reaction A(s) ⇌ M(s) + 1/2O₂(g) is Kₚ = 4. At…
• Solid carbon, CaO and CaCO₃ are mixed and allowed to attain equilibrium at T K . CaCO₃(…
• A box contains 0.90 g of liquid water in equilibrium with water vapour at 27°C. The…
• For a reaction at equilibrium A(g) ⇌ B(g) + 1/2 C(g) the relation between dissociation…
• For the reaction, H₂( g)+I₂( g)⇌ 2HI( g) Attainment of equilibrium is predicted…
• The ratio K_P/K_C for the reaction : CO_((g))+1/2O_(2( g))⇌ CO_(2( g)) is :
• One mole each of He and A(g) are taken in a 10 L closed flask and heated to 400 K to…
• In a closed flask at 600 K , one mole of X₂Y₄( g) attains equilibrium as given below…
• For the following gas phase equilibrium reaction at constant temperature, NH₃( g)⇌ 1/2…
• For the following reaction at 50°C and at 2 atm pressure, 2 N₂O₅( g)⇌ 2 N₂O₄( g)+O₂( g)…
• At 298 K, the equilibrium constant is 2× 10¹⁵ for the reaction : Cu(s)+2Ag⁺(aq)⇌…
• The following concentrations were observed at 500 K for the formation of NH₃ from N₂ and…
• Consider the reaction X₂Y( g)⇌ X₂( g)+1/2Y₂( g) The equation representing correct…
• Value of K P for the equilibrium reaction N₂O 4(g) ⇌ 2NO 2(g) at 288 K is 47.9. The K C…
• When 5.1 g of solid NH₄HS is introduced into a two litre evacuated flask at 27°C, 20% of…
• At T(K), the equilibrium constant of A₂(g)+B₂(g)⇌ C(g) is 2.7× 10⁻⁵. What is the…
• 2O₃(g) ⇌ 3O₂(g) At 300 K, ozone is fifty percent dissociated. The standard free energy…
• A(g)⇌ 2 B(g)+C(g) For the given reaction, if the initial pressure is 450 mm Hg and the…
• For the given reaction, choose the correct expression of K_C from the following :-…
• At 1990 K and 1 atm pressure, there are equal number of Cl₂, molecules and Cl atoms in…

Kc and Kp

• Consider the following reaction at 298 K · 3/2 O_(2(g)) ⇌ O_(3(g)) · K_P=2.47 × 10⁻²⁹…
• Assuming ideal behaviour, the magnitude of log K for the following reaction at 25°C is x…

Le Chatelier's Principle

• The effect of addition of helium gas to the following reaction in equilibrium state, is…
• Consider the following equation: 2SO₂(g)+O₂(g)⇌ 2SO₃(g),Δ H=-190 kJ The number of…
• Consider the following gaseous equilibrium in a closed container of volume ' V ' at…
• The following reaction occurs in the Blast furnance where iron ore is reduced to iron…
• In the following system, PCl₅( g)⇋ PCl₃( g)+Cl₂( g) at equilibrium, upon addition of…
• At 298 K N₂ (g)+3H₂ (g)⇌ 2NH₃ (g), K₁=4× 10⁵ N₂ (g)+O₂ (g)⇌ 2NO (g), K₂=1.6× 10¹² H₂…
• The equilibrium Cr₂ O₇²⁻ ⇌ 2 CrO₄²⁻ is shifted to the right in :
• The number of correct statement/s involving equilibria in physical processes from the…
• Consider the equilibrium CO(g)+3H₂( g)⇌ CH₄( g)+H₂O( g) If the pressure applied over the…

More Chemistry chapters

• Mole Concept & Stoichiometry
• Atomic Structure
• Gaseous State
• Chemical Thermodynamics
• Ionic Equilibrium
• Redox Reactions
• Solutions & Colligative Properties
• Electrochemistry
• Chemical Kinetics
• Solid State
• Surface Chemistry
• Nuclear & Radiochemistry
• Periodic Table & Periodicity
• Chemical Bonding & Molecular Structure
• Hydrogen & s-Block Elements
• p-Block Elements — Part I (Group 13 & 14)
• Environmental Chemistry
• p-Block Elements — Part II (Group 15-18)
• d & f Block Elements
• Coordination Compounds
• Metallurgy
• Qualitative Analysis — Salt Analysis
• Purification & Characterisation of Organic Compounds
• General Organic Chemistry (GOC)
• Hydrocarbons — Alkanes
• Hydrocarbons — Alkenes & Alkynes
• Hydrocarbons — Aromatic (Arenes)
• Halogen Derivatives — Haloalkanes & Haloarenes
• Alcohols, Phenols & Ethers
• Aldehydes & Ketones
• Carboxylic Acids & Their Derivatives
• Amines & Diazonium Salts
• Carbohydrates & Biomolecules
• Polymers
• Chemistry in Everyday Life
• Practical Organic Chemistry

Frequently asked questions

How many Chemical Equilibrium questions are there for JEE Main?

PrepWiser has 81 Chemical Equilibrium questions for JEE Main, grouped into 3 topics such as Law of Mass Action, Kc and Kp and Le Chatelier's Principle.

Are these Chemical Equilibrium questions from previous-year JEE Main papers?

Yes — most are genuine previous-year questions from past JEE Main papers, and the rest are practice questions written to match the JEE Main pattern and difficulty.

Where can I see the answers and solutions to these Chemical Equilibrium questions?

Open any Chemical Equilibrium question in PrepWiser (it is free) to attempt it; most come with a step-by-step solution.