JEE Main Chemistry Previous Year Questions with Solutions

JEE Main Chemistry Previous Year Questions (PYQs) with solutions are essential for mastering concepts and strengthening problem-solving skills. This section provides chapter-wise and topic-wise PYQs with clear, step-by-step solutions covering all major areas of Chemistry such as Physical, Organic, and Inorganic Chemistry. Practicing these questions helps students understand exam patterns, important concepts, and the application of reactions, formulas, and mechanisms. It also improves accuracy, speed, and confidence, making it a powerful tool for effective revision and success in JEE Main.

The complete JEE Main Chemistry syllabus is based on Class 11 and Class 12 topics, focusing on conceptual understanding and application-based questions. Regular practice of PYQs allows students to identify frequently asked topics and important trends in the examination.

JEE Main Chemistry Syllabus

PHYSICAL CHEMISTRY

UNIT I: SOME BASIC CONCEPTS IN CHEMISTRY

Matter and its nature, Dalton’s atomic theory, Concept of atom, molecule, element and compound, Laws of chemical combination, Atomic and molecular masses, mole concept, molar mass, percentage composition, empirical and molecular formulae, Chemical equations and stoichiometry.

UNIT 2: ATOMIC STRUCTURE

Nature of electromagnetic radiation, photoelectric effect, spectrum of the hydrogen atom, Bohr model of a hydrogen atom – its postulates, derivation of the relations for the energy of the electron and radii of the different orbits, limitations of Bohr’s model, dual nature of matter, de Broglie’s relationship, Heisenberg uncertainty principle, elementary ideas of quantum mechanics, the quantum mechanical model of the atom and its important features, concept of atomic orbitals as one-electron wave functions, variation of ψ and ψ² with r for 1s and 2s orbitals, various quantum numbers (principal, angular momentum and magnetic quantum numbers) and their significance, shapes of s, p and d – orbitals, electron spin and spin quantum number, rules for filling electrons in orbitals – Aufbau principle, Pauli’s exclusion principle and Hund’s rule, electronic configuration of elements and extra stability of half-filled and completely filled orbitals.

UNIT 3: CHEMICAL BONDING AND MOLECULAR STRUCTURE

Kossel-Lewis approach to chemical bond formation, the concept of ionic and covalent bonds.

Ionic Bonding: Formation of ionic bonds, factors affecting the formation of ionic bonds; calculation of lattice enthalpy.

Covalent Bonding: Concept of electronegativity, Fajan’s rule, dipole moment, Valence Shell Electron Pair Repulsion (VSEPR) theory and shapes of simple molecules.

Quantum mechanical approach to covalent bonding: Valence bond theory – its important features, the concept of hybridization involving s, p and d orbitals, resonance.

Molecular Orbital Theory – Its important features, LCAOs, types of molecular orbitals (bonding, antibonding), sigma and pi-bonds, molecular orbital electronic configurations of homonuclear diatomic molecules, the concept of bond order, bond length and bond energy.

Elementary idea of metallic bonding, hydrogen bonding and its applications.

UNIT 4: CHEMICAL THERMODYNAMICS

Fundamentals of thermodynamics: System and surroundings, extensive and intensive properties, state functions, entropy, types of processes.

The first law of thermodynamics – Concept of work, heat, internal energy and enthalpy, heat capacity, molar heat capacity, Hess’s law of constant heat summation, Enthalpies of bond dissociation, combustion, formation, atomization, sublimation, phase transition, hydration, ionization and solution.

The second law of thermodynamics – Spontaneity of processes, ΔS of the universe and ΔG of the system as criteria for spontaneity. ΔG° (Standard Gibbs energy change) and equilibrium constant.

UNIT 5: SOLUTIONS

Different methods for expressing the concentration of solution – molality, molarity, mole fraction, percentage (by volume and mass both), the vapour pressure of solutions and Raoult’s Law – Ideal and non-ideal solutions, vapour pressure – composition, plots for ideal and non-ideal solutions, Colligative properties of dilute solutions – a relative lowering of vapour pressure, depression of freezing point, the elevation of boiling point and osmotic pressure, determination of molecular mass using colligative properties, abnormal value of molar mass, van’t Hoff factor and its significance.

UNIT 6: EQUILIBRIUM

Meaning of equilibrium is the concept of dynamic equilibrium.

Equilibria involving physical processes: Solid-liquid, liquid-gas, gas-gas and solid-gas equilibria, Henry’s law. General characteristics of equilibrium involving physical processes.

Equilibrium involving chemical processes: Law of chemical equilibrium, equilibrium constants (Kp and Kc) and their significance, the significance of ΔG and ΔG° in chemical equilibrium, factors affecting equilibrium concentration, pressure, temperature, the effect of catalyst, Le Chatelier’s principle.

Ionic equilibrium: Weak and strong electrolytes, ionization of electrolytes, various concepts of acids and bases (Arrhenius, Bronsted-Lowry and Lewis) and their ionization, acid-base equilibria (including multistage ionization) and ionization constants, ionization of water, pH scale, common ion effect, hydrolysis of salts and pH of their solutions, the solubility of sparingly soluble salts, solubility products and buffer solutions.

UNIT 7: REDOX REACTIONS AND ELECTROCHEMISTRY

Electronic concepts of oxidation and reduction, redox reactions, oxidation number, rules for assigning oxidation number and balancing of redox reactions.

Electrolytic and metallic conduction, conductance in electrolytic solutions, molar conductivities and their variation with concentration, Kohlrausch’s law and its applications.

Electrochemical cells – Electrolytic and Galvanic cells, different types of electrodes, electrode potentials including standard electrode potential, half-cell and cell reactions, emf of a Galvanic cell and its measurement, Nernst equation and its applications, relationship between cell potential and Gibbs’ energy change, dry cell and lead accumulator, fuel cells.

UNIT 8: CHEMICAL KINETICS

Rate of a chemical reaction, factors affecting the rate of reactions: concentration, temperature, pressure and catalyst, elementary and complex reactions, order and molecularity of reactions, rate law, rate constant and its units, differential and integral forms of zero and first-order reactions, their characteristics and half-lives, the effect of temperature on the rate of reactions, Arrhenius theory, activation energy and its calculation, collision theory of bi-molecular gaseous reactions (no derivation).

INORGANIC CHEMISTRY

UNIT 9: CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES

Modern periodic law and present form of the periodic table, s, p, d and f block elements, periodic trends in properties of elements – atomic and ionic radii, ionization enthalpy, electron gain enthalpy, valence, oxidation states and chemical reactivity.

UNIT 10: p-BLOCK ELEMENTS

Group 13 to Group 18 Elements

General Introduction: Electronic configuration and general trends in physical and chemical properties of elements across the periods and down the groups, unique behaviour of the first element in each group.

UNIT 11: d- and f-BLOCK ELEMENTS

Transition Elements – General introduction, electronic configuration, occurrence and characteristics, general trends in properties of the first-row transition elements – physical properties, ionization enthalpy, oxidation states, atomic radii, colour, catalytic behaviour, magnetic properties, complex formation, interstitial compounds, alloy formation, preparation, properties and uses of K₂Cr₂O₇ and KMnO₄.

Inner Transition Elements:
Lanthanoids – Electronic configuration, oxidation states and lanthanoid contraction.
Actinoids – Electronic configuration and oxidation states.

UNIT 12: COORDINATION COMPOUNDS

Introduction to coordination compounds. Werner’s theory, ligands, coordination number, denticity, chelation, IUPAC nomenclature of mononuclear coordination compounds, isomerism.

Bonding: Valence bond approach and basic ideas of crystal field theory, colour and magnetic properties, importance of coordination compounds (in qualitative analysis, extraction of metals and in biological systems).

ORGANIC CHEMISTRY

UNIT 13: PURIFICATION AND CHARACTERISATION OF ORGANIC COMPOUNDS

Purification – Crystallization, sublimation, distillation, differential extraction and chromatography – principles and their applications.

Qualitative analysis – Detection of nitrogen, sulphur, phosphorus and halogens.

Quantitative analysis (basic principles only) – Estimation of carbon, hydrogen, nitrogen, halogens, sulphur and phosphorus. Calculations of empirical formulae and molecular formulae, numerical problems in organic quantitative analysis.

UNIT 14: SOME BASIC PRINCIPLES OF ORGANIC CHEMISTRY

Tetravalency of carbon, shapes of simple molecules – hybridization (s and p), classification of organic compounds based on functional groups and those containing halogens, oxygen, nitrogen and sulphur, homologous series.

Isomerism – structural and stereoisomerism. Nomenclature (Trivial and IUPAC).

Covalent bond fission – Homolytic and heterolytic, free radicals, carbocations and carbanions, stability of carbocations and free radicals, electrophiles and nucleophiles.

Electronic displacement in a covalent bond – Inductive effect, electromeric effect, resonance and hyperconjugation.

Common types of organic reactions – Substitution, addition, elimination and rearrangement.

UNIT 15: HYDROCARBONS

Classification, isomerism, IUPAC nomenclature, general methods of preparation, properties and reactions.

Alkanes – Conformations: Sawhorse and Newman projections (of ethane), mechanism of halogenation of alkanes.

Alkenes – Geometrical isomerism, mechanism of electrophilic addition, addition of hydrogen, halogens, water, hydrogen halides (Markovnikov and peroxide effect), ozonolysis and polymerization.

Alkynes – Acidic character, addition of hydrogen, halogens, water and hydrogen halides, polymerization.

Aromatic hydrocarbons – Nomenclature, benzene – structure and aromaticity, mechanism of electrophilic substitution, halogenation, nitration, Friedel-Crafts alkylation and acylation, directive influence of the functional group in mono-substituted benzene.

UNIT 16: ORGANIC COMPOUNDS CONTAINING HALOGENS

General methods of preparation, properties and reactions, nature of C–X bond, mechanisms of substitution reactions. Uses, environmental effects of chloroform, iodoform, freons and DDT.

UNIT 17: ORGANIC COMPOUNDS CONTAINING OXYGEN

General methods of preparation, properties, reactions and uses.

Alcohols, Phenols and Ethers:
Alcohols – Identification of primary, secondary and tertiary alcohols, mechanism of dehydration.
Phenols – Acidic nature, electrophilic substitution reactions, halogenation, nitration and sulphonation, Reimer-Tiemann reaction.
Ethers – Structure.

Aldehydes and Ketones – Nature of carbonyl group, nucleophilic addition to >C=O group, relative reactivities of aldehydes and ketones, important reactions such as nucleophilic addition (HCN, NH₃ derivatives), Grignard reagent, oxidation, reduction (Wolff-Kishner and Clemmensen), acidity of α-hydrogen, Aldol condensation, Cannizzaro reaction, Haloform reaction, chemical tests to distinguish between aldehydes and ketones.

Carboxylic Acids – Acidic strength and factors affecting it.

UNIT 18: ORGANIC COMPOUNDS CONTAINING NITROGEN

General methods of preparation, properties, reactions and uses.

Amines – Nomenclature, classification, structure, basic character and identification of primary, secondary and tertiary amines.

Diazonium Salts – Importance in synthetic organic chemistry.

UNIT 19: BIOMOLECULES

General introduction and importance of biomolecules.

Carbohydrates – Classification, aldoses and ketoses, monosaccharides (glucose and fructose), oligosaccharides (sucrose, lactose and maltose).

Proteins – Elementary idea of α-amino acids, peptide bond, polypeptides, protein structure (primary, secondary, tertiary, quaternary), denaturation, enzymes.

Vitamins – Classification and functions.

Nucleic Acids – DNA and RNA, biological functions.

Hormones – General introduction.

UNIT 20: PRINCIPLES RELATED TO PRACTICAL CHEMISTRY

Detection of extra elements (N, S, halogens) and functional groups (alcoholic, phenolic, carbonyl, carboxyl, amino).

Preparation of compounds: Mohr’s salt, potash alum, acetanilide, p-nitroacetanilide, aniline yellow, iodoform.

Titrimetric exercises – acids, bases, indicators, oxalic acid vs KMnO₄, Mohr’s salt vs KMnO₄.

Qualitative salt analysis:
Cations – Pb²⁺, Cu²⁺, Al³⁺, Fe³⁺, Zn²⁺, Ni²⁺, Ca²⁺, Ba²⁺, Mg²⁺, NH₄⁺
Anions – CO₃²⁻, S²⁻, SO₄²⁻, NO₃⁻, NO₂⁻, Cl⁻, Br⁻, I⁻

Experiments:

1. Enthalpy of solution of CuSO₄
2. Enthalpy of neutralization
3. Preparation of sols
4. Kinetics of iodide ions with hydrogen peroxide

 

JEE Main Chemistry PYQs Learning Approach

Practicing JEE Main Chemistry PYQs helps students develop a deeper understanding of concepts and improves their ability to apply knowledge in different types of questions. This section includes detailed solutions, shortcut techniques, and exam-oriented strategies to enhance performance.

Summary

JEE Main Chemistry PYQs serve as a complete and reliable resource for students preparing for the exam. With structured practice, detailed explanations, and consistent revision, students can significantly improve their accuracy, speed, and overall performance. Stay consistent, focus on concepts, and make PYQs a regular part of your preparation to achieve success in JEE Main.