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Class 11 Chemistry — Chapter 1: Some Basic Concepts of Chemistry

90 practice questions · 30 Easy · 30 Medium · 30 Hard

Practise Class 11 Chemistry Chapter 1, "Some Basic Concepts of Chemistry", with 90 NCERT-aligned multiple-choice questions. The set is split into 30 Easy, 30 Medium and 30 Hard questions, so you can warm up on the fundamentals and then push into the exam-level problems that separate top scorers in CBSE Board exams, JEE Main, JEE Advanced and NEET UG.

"Some Basic Concepts of Chemistry" is one of the chapters where reactions, named concepts, and balanced numerical work really pays off. Each MCQ on this chapter is timed and uses exam-grade marking (+2 correct, −1 wrong, 0 skipped), training the same accuracy-under-pressure that real papers demand. Every question carries a short explanation, so a wrong answer becomes a quick lesson rather than a dead end — the fastest way to close gaps before a test.

Use this chapter as targeted revision: attempt the Easy set first to confirm your basics on Some Basic Concepts of Chemistry, then move to Medium and Hard to test application and problem-solving. Your accuracy, streaks and XP save automatically, and the chapter feeds into your overall Class 11 Chemistry mastery score. A few sample questions are shown below; sign in free to practise all 90.

Key concepts: Some Basic Concepts of Chemistry (Class 11 Chemistry)

This chapter covers the laws of chemical combination, the mole concept, stoichiometry, and concentration terms.

Laws of chemical combination
Conservation of mass, constant proportions, multiple proportions and Gay-Lussac's law of gaseous volumes.
Mole concept
One mole = 6.022 × 10²³ particles (Avogadro's number) = the molar mass in grams.
Stoichiometry
Quantitative relations in a balanced equation; the limiting reagent decides how much product forms.
Empirical & molecular formula
Empirical gives the simplest ratio of atoms; molecular = n × empirical formula.
Concentration terms
Molarity (mol/L), molality (mol/kg), mole fraction and mass percentage express solution strength.

Key formulas — Some Basic Concepts of Chemistry

Moles from mass
n = mass / molar mass
Molarity
M = moles of solute / volume of solution (L)
Number of particles
N = n × 6.022 × 10²³

💡 Exam tips for Some Basic Concepts of Chemistry

  • Identify the limiting reagent first — it controls the maximum amount of product.
  • Molality is temperature-independent (uses mass), unlike molarity (uses volume).

Sample questions

Q1Easy

Molar mass of H₂O:

A.18 g/mol✓ correct
B.20 g/mol
C.16 g/mol
D.2 g/mol
Why

2(1) + 16 = 18.

Q2Medium

Moles in 36 g of water:

A.2✓ correct
B.1
C.36
D.18
Why

36/18 = 2 mol.

Q3Hard

Empirical formula of glucose (C₆H₁₂O₆):

A.CH₂O✓ correct
B.C₂H₄O
C.CHO
D.C₆H₁₂O₆
Why

Divide by 6.

Some Basic Concepts of Chemistry — FAQs

What are the key concepts in Class 11 Chemistry Some Basic Concepts of Chemistry?+

This chapter covers the laws of chemical combination, the mole concept, stoichiometry, and concentration terms. Key ideas include Laws of chemical combination, Mole concept, Stoichiometry, Empirical & molecular formula, Concentration terms.

What does Class 11 Chemistry Chapter 1 (Some Basic Concepts of Chemistry) cover on XamBaaz?+

It covers 90 NCERT-aligned MCQs on "Some Basic Concepts of Chemistry" — 30 Easy, 30 Medium and 30 Hard — each with a timed quiz and an instant explanation, suitable for CBSE Board exams, JEE Main, JEE Advanced and NEET UG.

Are these "Some Basic Concepts of Chemistry" questions free to practise?+

Yes — sign in with Google to practise "Some Basic Concepts of Chemistry" free. Full unlimited access is ₹999/year (limited-time launch price), with no per-chapter charges.

How should I revise "Some Basic Concepts of Chemistry" for the exam?+

Start with the Easy quiz to confirm your fundamentals, then attempt Medium and Hard for application-level practice. Review each explanation, retry the questions you miss, and track your accuracy on this chapter until it is consistently high.

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