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Mole Concept & Stoichiometry JEE Main PYQs, 2020 to 2025

Mole Concept & Stoichiometry has 133 questions in JEE Main papers from 2020 to 2025, about 22 per year across all shifts. The most asked topic is Stoichiometry (57 questions), followed by Concentration Terms (44) and Empirical and Molecular Formula (15).

Updated

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133Total PYQs
6Years covered
5Topics
2025 Apr S2Latest paper

Mole Concept & Stoichiometry questions per year

YearQuestions
202519
202422
202325
202226
202123
202018

Topic-wise weightage

TopicQuestionsShare of chapterLast asked
Stoichiometry5743%2025
Concentration Terms4433%2025
Empirical and Molecular Formula1511%2025
Limiting Reagent97%2025
Atomic and Molar Mass86%2025

Sample questions from recent papers

JEE Main 2025 · 7 Apr · Shift 2 · Limiting Reagent

Butane reacts with oxygen to produce carbon dioxide and water following the equation given below.

C4H10( g)+132O2( g)→4CO2( g)+5H2O(l)\mathrm{C}_4 \mathrm{H}_{10}(\mathrm{~g})+\frac{13}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow 4 \mathrm{CO}_2(\mathrm{~g})+5 \mathrm{H}_2 \mathrm{O}(\mathrm{l})

If 174.0 kg of butane is mixed with 320.0 kg of O2\mathrm{O}_2, the volume of water formed in liters is

_____________. (Nearest integer)

[Given : (a) Molar mass of C, H, O are 12,1,16 g mol−112,1,16 \mathrm{~g} \mathrm{~mol}^{-1} respectively, (b) Density of water =1 g mL−1]\left.=1 \mathrm{~g} \mathrm{~mL}^{-1}\right]

Answer: 138

Step-by-step solution

JEE Main 2025 · 4 Apr · Shift 2 · Stoichiometry

The amount of calcium oxide produced on heating 150 kg limestone ( 75%75 \% pure) is _________ kg. (Nearest integer)

Given: Molar mass (in gmol−1\mathrm{g} \mathrm{mol}^{-1} ) of Ca-40, O-16, C-12

Answer: 63

Step-by-step solution

JEE Main 2025 · 4 Apr · Shift 1 · Concentration Terms

Fortification of food with iron is done using FeSO4⋅7H2O\mathrm{FeSO}_4 \cdot 7 \mathrm{H}_2 \mathrm{O}. The mass in grams of the FeSO4\mathrm{FeSO}_4. 7H2O7 \mathrm{H}_2 \mathrm{O} required to achieve 12 ppm of iron in 150 kg of wheat is ______ (Nearest integer)

[Given: Molar mass of Fe,S\mathrm{Fe}, \mathrm{S} and and O respectively are 56, 32 and 16 g mol−116 \mathrm{~g} \mathrm{~mol}^{-1} ]

Answer: 9

Step-by-step solution

JEE Main 2025 · 3 Apr · Shift 1 · Atomic and Molar Mass

Among 10−9 g10^{-9} \mathrm{~g} (each) of the following elements, which one will have the highest number of atoms?

Element: Pb,Po,Pr\mathrm{Pb}, \mathrm{Po}, \mathrm{Pr} and Pt

  1. (A) Pr
  2. (B) Pt
  3. (C) Po
  4. (D)Pb

Answer: (A)

Step-by-step solution

JEE Main 2025 · 2 Apr · Shift 1 · Empirical and Molecular Formula

On complete combustion 1.0 g of an organic compound (X)(\mathrm{X}) gave 1.46 g of CO2\mathrm{CO}_2 and 0.567 g of H2O\mathrm{H}_2 \mathrm{O}. The empirical formula mass of compound (X)(\mathrm{X}) is __________ g. (Given molar mass in gmol−1C:12,H:1,O:16\mathrm{g} \mathrm{mol}^{-1} \mathrm{C}: 12, \mathrm{H}: 1, \mathrm{O}: 16 )

  1. (A)60
  2. (B)45
  3. (C)30
  4. (D)15

Answer: (C)

Step-by-step solution

All 133 questions are in the free PDF above, grouped by topic.

Frequently asked

How many questions come from Mole Concept & Stoichiometry in JEE Main?

133 questions from 2020 to 2025, about 22 per year. In 2025 it had 19.

Which Mole Concept & Stoichiometry topics are most important for JEE Main?

By past papers: Stoichiometry (43%), Concentration Terms (33%) and Empirical and Molecular Formula (11%) of all Mole Concept & Stoichiometry questions.

Is the Mole Concept & Stoichiometry 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.

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

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