Mole Concept - JEE Advanced Previous Year Questions with Solutions
Practice JEE Advanced Mole Concept questions covering atomic mass calculation, molarity, molality, density-based problems, mole fraction, and concentration relationships to strengthen numerical problem-solving skills in physical chemistry.
Table of Contents
eSaral › JEE › JEE Main ›Mole Concept - JEE Advanced Previous Year Questions with Solutions
🚀 Checkout eSaral Courses
Why Mole Concept Matters in JEE Advanced
The mole concept is the foundation of physical chemistry. In JEE Advanced, it appears both as a standalone topic and as the entry point for questions on solutions, electrochemistry, and chemical equilibrium. According to the NTA's official JEE Advanced syllabi, mole concept falls under Physical Chemistry – Basic Concepts, a section that has contributed 1–3 questions in nearly every JEE Advanced paper since 2009.
What makes these questions tricky is not the formula — it is the unit conversion. Students who can mechanically apply the molarity formula still lose marks because they miss a density conversion from g/cm³ to kg/L, or confuse volume of solution with volume of solvent.
Mole Concept - JEE Advanced Previous Year Questions with Solutions
JEE Advanced Previous Year Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Advanced Previous Year Papers Questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas.
Frequently Asked Questions
Find answers to common questions.
How many questions come from the mole concept in JEE Advanced?
Typically 1–2 questions appear from mole concept in JEE Advanced each year, usually in Paper 1. They are often integer-type or single-correct MCQs. While the weightage is not the highest, these questions are considered scoring because the formulas are fixed and errors are avoidable with careful unit management.
Is mole concept important for JEE Advanced or only JEE Main?
Mole concept is tested in both JEE Main and JEE Advanced. In JEE Advanced, the questions are more application-based — for example, combining density, Avogadro's number, and surface area in a single problem (as seen in the 2010 silver atoms question). It also acts as a prerequisite for electrochemistry and solution chemistry at the JEE Advanced level.
What is the fastest way to calculate average atomic mass in JEE?
Use the weighted average formula directly: M_avg = Σ(mass of isotope × abundance%) ÷ 100. Do not divide by the number of isotopes. For the 2009 Fe question, this gives (54×5 + 56×90 + 57×5) ÷ 100 = 55.95. This formula works for any number of isotopes and takes under 30 seconds with practice.
What is the difference between molarity and molality in JEE problems?
Molarity (M) = moles of solute per litre of solution — it changes with temperature because volume changes. Molality (m) = moles of solute per kilogram of solvent — it is temperature-independent. In JEE Advanced 2016, the question exploited the condition where M = m at a specific density and mole fraction to find a molecular weight ratio.
Are there mole concept questions in JEE Advanced after 2016?
Yes. While this page currently covers 2009–2016, mole concept continues to appear post-2016, often embedded within thermochemistry, solutions, or electrochemistry questions rather than as a standalone topic. Checking the full JEE Advanced question papers year-wise on eSaral will give you the most current coverage.