Mole Concept & Stoichiometry — JEE Main PYQs & Practice Questions

Mole Concept & Stoichiometry is a Chemistry chapter in the JEE Main syllabus. This page brings together 204 previous-year and practice questions on Mole Concept & Stoichiometry, organised into 6 topics: Atomic and Molar Mass, Empirical and Molecular Formula, Stoichiometry, Limiting Reagent, Percentage Yield and Purity and Concentration Terms. Most questions come with a step-by-step solution you can work through free in PrepWiser.

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

Atomic and Molar Mass

• Among 10⁻⁹ g (each) of the following elements, which one will have the highest number of…
• Choose the Incorrect Statement about Dalton's Atomic Theory
• The candela is the luminous intensity, in a given direction, of a source that emits…
• Match List I with List II List - I | List - II (Δ₀); A. | 16 g of CH₄ (g) | I. | Weighs…
• A sample of 4.5 mg of an unknown monohydric alcohol, R-OH was added to methylmagnesium…
• The number of atoms in 8g of sodium is x × 10²³. The value of x is ____________…
• The incorrect postulates of the Dalton's atomic theory are : (A) Atoms of different…
• Using the rules for significant figures, the correct answer for the expression (0.02858…
• The number of significant figures in 50000.020 × 10⁻³ is _____________.
• A protein 'A' contains 0.30% of glycine (molecular weight 75). The minimum molar mass of…
• Amongst the following statements, that which was not proposed by Dalton was :
• The average molar mass of chlorine is 35.5 g mol –1 . The ratio of ³⁵Cl to ³⁷Cl in…
• Which of the following have same number of significant figures? A. 0.00253 B. 1.0003 C…
• Choose the correct statements. (A) Weight of a substance is the amount of matter present…
• The number of significant figures in 0.00340 is ____________.
• Which of the following contain the same number of atoms? (Given : Molar mass in gmol⁻¹…
• Hemoglobin contains 0.34 % of iron by mass. The number of Fe atoms in 3.3 g of…
• 0.1 mol of the following given antiviral compound (P) will weigh ________ × 10⁻¹ g…
• Match List - I with List - II. List - I Mass of substance | List - II Number of atoms…
• A chloro compound "A". (i) forms aldehydes on ozonolysis followed by the hydrolysis…

Empirical and Molecular Formula

• 0.5 g of an organic compound (X) with 60 % carbon will produce __________ × 10⁻¹ g of…
• 80 mL of a hydrocarbon on mixing with 264 mL of oxygen in a closed U-tube undergoes…
• Complete combustion of 750 g of an organic compound provides 420 g of CO₂ and 210 g of…
• 0.01 mole of an organic compound (X) containing 10 % hydrogen, on complete combustion…
• On complete combustion 1.0 g of an organic compound (X) gave 1.46 g of CO₂ and 0.567 g…
• Quantitative analysis of an organic compound (X) shows following % composition. C : 14.5…
• Number of hydrogen atoms per molecule of a hydrocarbon A having 85.8% carbon is…
• Compound A contains 8.7% Hydrogen, 74% Carbon and 17.3% Nitrogen. The molecular formula…
• Uracil is a base present in RNA with the following structure. % of N in uracil is…
• The number of hydrogen atoms in toluene (C₇H₈) is x.
• The complete combustion of 0.492 g of an organic compound containing 'C', 'H' and 'O'…
• On complete combustion of 0.492 g of an organic compound containing C, H and O, 0.7938 g…
• An organic compound has 42.1 % carbon, 6.4 % hydrogen and remainder is oxygen. If its…
• An oxide of iron contains 69.9% iron, its empirical formula, is : (Given : Molar mass of…
• A metal chloride contains 55.0 % of chlorine by weight . 100 mL vapours of the metal…
• The ratio of number of water molecules in Mohr's salt and potash alum is ____________ ×…
• The cycloalkene (X) on bromination consumes one mole of bromine per mole of (X) and…
• Thyroxine, the hormone has given below structure The percentage of iodine in thyroxine…
• 116 g of a substance upon dissociation reaction, yields 7.5 g of hydrogen, 60 g of…
• The elemental composition of a compound is 54.2 % C, 9.2 % H and 36.6 % O. If the molar…

Stoichiometry

• SO₂ Cl₂ on reaction with excess of water results into acidic mixture SO₂ Cl₂+2 H₂ O → H₂…
• For a reaction, N₂ O_(5( g)) → 2 NO_(2( g))+1/2 O_(2( g)) in a constant volume…
• The ammonia (NH₃) released on quantitative reaction of 0.6 g urea (NH₂CONH₂) with sodium…
• 2L of 0.2M H₂SO₄ is reacted with 2L of 0.1M NaOH solution, the molarity of the resulting…
• In the reaction, 2Al( s)+6HCl(aq)→ 2Al³⁺(aq)+6Cl⁻(aq)+3H₂( g)
• The ratio of number of oxygen atoms to bromine atoms in the product Q is _________ × 10⁻¹.
• 100 g of propane is completely reacted with 1000 g of oxygen. The mole fraction of…
• The density of a monobasic strong acid (Molar mass 24.2 g/mol) is 1.21 kg/L. The volume…
• Mass of magnesium required to produce 220 mL of hydrogen gas at STP on reaction with…
• Number of moles of methane required to produce 22 g CO_(2( g)) after combustion is x ×…
• The moles of methane required to produce 81 g of water after complete combustion is…
• CNG is an important transportation fuel. When 100 g CNG is mixed with 208 g oxygen in…
• The ratio of the mass percentages of ‘C & H’ and ‘C & O’ of a saturated acyclic organic…
• 10 mL of gaseous hydrocarbon on combustion gives 40 mL of CO₂( g) and 50 mL of water…
• If 279 g of aniline is reacted with one equivalent of benzenediazonium chloride, the…
• x mg of pure HCl was used to make an aqueous solution. 25.0 mL of 0.1MBa(OH)₂ solution…
• Zinc reacts with hydrochloric acid to give hydrogen and zinc chloride. The volume of…
• The volume of hydrogen liberated at STP by treating 2.4 g of magnesium with excess of…
• 20 mL of sodium iodide solution gave 4.74 g silver iodide when treated with excess of…
• The ratio of mass percentage (w/w) of C : H in a hydrocarbon is 12 : 1. It has two…

Limiting Reagent

• Production of iron in blast furnace follows the following equation Fe₃O₄(s) + 4CO(g) →…
• Butane reacts with oxygen to produce carbon dioxide and water following the equation…
• In the given reaction, X+Y+3 Z ⇄ X YZ₃ if one mole of each of X and Y with 0.05 mol of Z…
• N_(2( g))+3 H_(2( g)) ⇌ 2 NH_(3( g)) 20 g 5 g Consider the above reaction, the limiting…
• For the given reaction; CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂ If 90 g CaCO₃ is added to 300…
• Blister copper is produced by reaction of copper oxide with copper sulphide. 2Cu₂O +…
• CaCO₃( s)+2 HCl(aq) → CaCl₂(aq)+CO₂( g)+H₂ O(l) Consider the above reaction, what mass…
• When 81.0 g of aluminium is allowed to react with 128.0 g of oxygen gas, the mass of…
• A+2 B→ AB₂ 36.0 g of 'A' (Molar mass : 60 g mol⁻¹ ) and 56.0 g of ' B ' (Molar mass : 80…
• What volume of hydrogen gas at STP would be liberated by action of 50 mL of H₂SO₄ of 50%…
• Consider the following reaction : 3 PbCl₂+2(NH₄)₃ PO₄ → Pb₃(PO₄)₂+6 NH₄ Cl If 72 mmol of…
• Consider the following reaction occurring in the blast furnace: Fe₃ O₄₍ₛ₎+4 CO_((g)) → 3…
• When 35 mL of 0.15 M lead nitrate solution is mixed with 20 mL of 0.12 M chromic…
• If 5 moles of BaCl₂ is mixed with 2 moles of Na₃ PO₄, the maximum number of moles of…

Percentage Yield and Purity

• Consider the above reaction where 6.1 g of Benzoic acid is used to get 7.8 g of m-bromo…
• In the following reaction The % yield for reaction I is 60 % and that of reaction II is…
• In the above reaction, 5 g of toluene is converted into benzaldehyde with 92% yield. The…
• Methylation of 10 g of benzene gave 9.2 g of toluene. Calculate the percentage yield of…
• 1.86 g of aniline completely reacts to form acetanilide. 10% of the product is lost…
• In the above reaction, 3.9 g of benzene on nitration gives 4.92 g of nitrobenzene. The…
• In bromination of Propyne, with Bromine, 1, 1, 2, 2-tetrabromopropane is obtained in 27%…
• The mass of benzanilide obtained from the benzoylation reaction of 5.8 g of aniline, if…
• 4.7 g of phenol is heated with Zn to give product X . If this reaction goes to 60%…
• A student has planned to prepare acetanilide from aniline using acetic anhydride. The…
• 9.3 g of pure aniline is treated with bromine water at room temperature to give a white…
• __________ grams of 3-Hydroxy propanal (MW = 74) must be dehydrated to produce 7.8 g of…
• Consider the above reaction. The percentage yield of amide product is __________. (Round…
• Consider the above sequence of reactions. 151 g of 2-bromopentane is made to react…
• In the Claisen-Schmidt reaction to prepare, dibenzalacetone from 5.3 g of benzaldehyde…

Concentration Terms

• Some amount of dichloromethane (CH₂ Cl₂) is added to 671.141 mL of chloroform (CHCl₃) to…
• 10.0 mL of Na₂CO₃ solution is titrated against 0.2 M HCl solution. The following titre…
• Molality of an aqueous solution of urea is 4.44 m. Mole fraction of urea in solution is…
• At T(K),100 g of 98%H₂SO₄(w/w) aqueous solution is mixed with 100 g of 49%H₂SO₄(w/w)…
• If the concentration of glucose (C₆H₁₂O₆) in blood is 0.72 g L⁻¹, the molarity of…
• Consider titration of NaOH solution versus 1.25 M oxalic acid solution. At the end point…
• 250 g solution of D-glucose in water contains 10.8 % of carbon by weight. The molality…
• The mole fraction of a solute in a 100 molal aqueous solution is ___________ × 10⁻²…
• A solution of sugar is obtained by mixing 200 g of its 25 % solution and 500 g of its 40…
• The molarity of HNO₃in a sample which has density 1.4 g/mL and mass percentage of 63% is…
• 100 mL of Na₃PO₄ solution contains 3.45 g of sodium. The molarity of the solution is…
• What is the mole fraction of water in 10% by weight (w/w) of aqueous urea solution?…
• A 100 mL solution was made by adding 1.43 g of Na₂CO₃.xH₂O. The normality of the…
• The molality of a 10 %(v / v) solution of di-bromine solution in CCl₄ (carbon…
• Given below are two statements: one is labelled as Assertion A and the other is labelled…
• The molarity of a 70 % (mass/mass) aqueous solution of a monobasic acid (X) is _________…
• The Molarity (M) of an aqueous solution containing 5.85 g of NaCl in 500 mL water is…
• When 800 mL of 0.5 M nitric acid is heated in a beaker, its volume is reduced to half…
• 5 g of NaOH was dissolved in deionized water to prepare a 450 mL stock solution. What…
• The strengths of 5.6 volume hydrogen peroxide (of density 1 g/mL) in terms of mass…

More Chemistry chapters

• Atomic Structure
• Gaseous State
• Chemical Thermodynamics
• Chemical Equilibrium
• 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 Mole Concept & Stoichiometry questions are there for JEE Main?

PrepWiser has 204 Mole Concept & Stoichiometry questions for JEE Main, grouped into 6 topics such as Atomic and Molar Mass, Empirical and Molecular Formula and Stoichiometry.

Are these Mole Concept & Stoichiometry 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 Mole Concept & Stoichiometry questions?

Open any Mole Concept & Stoichiometry question in PrepWiser (it is free) to attempt it; most come with a step-by-step solution.