IEMJEE Chemistry preparation: The mole and molar mass — practice worksheet with answers

How to use this worksheet

This independent worksheet checks the mole and molar mass with a new problem, an explanation task and an interleaved related skill. It is not an official IEM question paper, a difficulty forecast or a prescribed timed examination.

Write an attempt first, then compare your method with the visible answers. Record whether a miss came from interpretation, a missing concept, execution or a condition you overlooked.

Question 1: apply the topic

Using M(CO₂)=44 g/mol, find mass of 0.5 mol.

Answer and checking point

m=nM=0.5×44=22 g.

Check atom and charge bookkeeping, units, signs and the identity of the species to which a statement applies. For an organic transformation, retain the substrate and conditions. A familiar reagent or periodic trend is not enough to prove every proposed product or comparison.

Question 2: diagnose an approach

Explain why the following warning matters and identify the correction it calls for: A molar mass in g/mol must not be combined with a mass still expressed in kilograms without conversion.

Model checkpoint: A mole counts entities through amount of substance. Molar mass converts between measured mass and amount. Governing rule: n=m/M with compatible mass units.

Question 3: transfer to ph of strong-acid solutions

If [H⁺] becomes ten times larger, how does pH change?

Answer: It decreases by one unit.

This is an interleaved related-skill task, not a claim that the two topics have identical methods. Explain which idea changes when switching from the main topic to this one.

Review the attempt

Separate correct answers reached with a justified method from lucky guesses. Rework missed steps without looking at the answer, then use a fresh problem from an appropriate primary textbook or official paper. Do not use a small worksheet result as an admission cutoff, rank or readiness guarantee.

Official sources and verification

Sources checked on 26 October 2026. A source’s date, programme and campus limit which claims it supports. Official pages may change after review.

1. UEM — IEMJEE examination information

   Historical examination pattern; verify the current cycle on the central portal.

2. NTA — explicitly labelled JEE Main 2026 syllabus

   Historical PCM syllabus reference. Lessons and exercises are independently authored, not official IEMJEE papers or verified 2027 paper predictions.

3. NCERT — official textbook catalogue

   Primary textbook reference for checking school-level concepts. This directory does not certify the independent lesson or establish IEM examination weightage.

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