States of Matter — Class 11 MCQs with Answers
Class 11 CBSE Chemistry · Chapter 305
40 practice questions · 20 Easy · 20 Medium · Updated
Practise the most important Class 11 CBSE Chemistry questions from Chapter 305, "States of Matter". You get 4 timed quizzes made from 40 NCERT-based MCQs, with answers and explanations. The questions are split into 20 Easy and 20 Medium. Warm up on the basics, then move on to the exam-level questions that set top scorers in CBSE & Maharashtra HSC Board exams, JEE Main, MHT-CET, JEE Advanced and NEET UG apart.
To score well in "States of Matter", focus on reactions, key concepts and careful numericals. Each MCQ here is timed and uses exam-style marking (+4 correct, −1 wrong, 0 skipped). This trains you to stay accurate under time pressure, as real papers need. Every question has a short explanation, so a wrong answer becomes a quick lesson. It is the fastest way to fix gaps before a test.
Use this chapter for focused revision. Start with the Easy set to check your basics on States of Matter, then move to Medium to practise applying them. Your accuracy, streaks and XP save automatically. This chapter also adds to your overall Class 11 Chemistry mastery score. 6 sample questions are solved in full below, with the answer and a worked explanation. Sign in free to start practising.
Key concepts: States of Matter (Class 11 Chemistry)
Whether a substance is a gas, a liquid or a solid is decided by a tug of war between the intermolecular forces pulling its particles together and the thermal energy driving them apart. This chapter first surveys those forces — London dispersion, dipole-dipole and hydrogen bonding — and then studies the gaseous state in detail: the laws of Boyle, Charles, Gay-Lussac and Avogadro, which combine into the ideal gas equation PV = nRT, together with Dalton's law of partial pressures and Graham's law of diffusion. The kinetic molecular theory explains why these laws work and introduces the Maxwell distribution of molecular speeds. Finally, real gases are shown to deviate from ideality at high pressure and low temperature, a deviation measured by the compressibility factor and described by the van der Waals equation, which leads on to critical constants, liquefaction and the properties of the liquid state.
- London dispersion forces
- Momentary fluctuations in the electron cloud of an atom or molecule create an instantaneous dipole that induces a dipole in its neighbour. These forces act between all particles, including non-polar ones such as He and CH₄, and grow stronger as the number of electrons and the size of the molecule increase.
- Dipole-dipole interaction
- Molecules with a permanent dipole moment, such as HCl or SO₂, line up so that the positive end of one faces the negative end of the next. These attractions are stronger than dispersion forces between molecules of comparable size, so polar substances usually boil higher than non-polar ones.
- Hydrogen bonding
- A special, unusually strong dipole-dipole attraction that arises when hydrogen is covalently bonded to the small, highly electronegative atoms F, O or N. It explains the abnormally high boiling points of HF, H₂O and NH₃, the high viscosity of glycerol, and the fact that ice is less dense than water.
- Boyle's law
- At constant temperature, the volume of a fixed mass of gas varies inversely with the pressure, so that PV stays constant. A plot of P against V is a hyperbola while a plot of P against 1/V is a straight line through the origin, which is the usual way of testing the law.
States of Matter — important questions & MCQs with answers (Class 11 Chemistry)
6 solved questions from this chapter's difficulty levels, each with its answer and explanation. The other 34 are timed and scored when you sign in.
- Q1Easy
The weakest intermolecular force, which is present even between the atoms of a noble gas such as argon, is
A.the hydrogen bondB.the ion-dipole forceC.the London dispersion force✓ CorrectD.the covalent bondAnswer: C. the London dispersion force
Explanation: Momentary shifts in the electron cloud create instantaneous dipoles, so London dispersion forces act between all particles, including non-polar atoms like argon.
- Q2Easy
Boyle's law states that for a fixed mass of gas
A.V ∝ T at constant pressureB.V ∝ 1/P at constant temperature✓ CorrectC.P ∝ T at constant volumeD.V ∝ n at constant temperature and pressureAnswer: B. V ∝ 1/P at constant temperature
Explanation: Boyle's law is the pressure-volume law: at constant temperature the volume of a fixed mass of gas varies inversely with pressure, so PV is constant.
- Q3Easy
The temperature above which a gas cannot be liquefied however great the pressure applied is called its
A.boiling pointB.Boyle temperatureC.critical temperature✓ CorrectD.inversion temperatureAnswer: C. critical temperature
Explanation: Above the critical temperature the molecules have too much kinetic energy for the attractive forces to hold them together, so no amount of pressure produces a liquid.
- Q4Medium
Which of the following hydrogen halides has the highest boiling point?
A.HClB.HBrC.HF✓ CorrectD.HIAnswer: C. HF
Explanation: HF molecules are linked by strong hydrogen bonds, which outweigh the steadily rising dispersion forces down the series HCl < HBr < HI, so HF boils highest of the four.
- Q5Medium
A gas occupies 500 mL at a pressure of 1 atm. At the same temperature, what volume will it occupy when the pressure is raised to 2.5 atm?
A.200 mL✓ CorrectB.250 mLC.1250 mLD.400 mLAnswer: A. 200 mL
Explanation: By Boyle's law P₁V₁ = P₂V₂, so V₂ = (1 × 500)/2.5 = 200 mL. Raising the pressure 2.5 times shrinks the volume to 1/2.5 of its original value.
- Q6Medium
In the van der Waals equation (P + an²/V²)(V − nb) = nRT, the constant b corrects for
A.the attractive forces between the moleculesB.the finite volume actually occupied by the gas molecules✓ CorrectC.the elastic nature of collisions with the wallsD.the loss of kinetic energy during collisionsAnswer: B. the finite volume actually occupied by the gas molecules
Explanation: The term nb is the excluded volume of the molecules themselves and is subtracted from V, while an²/V² is the pressure correction for intermolecular attraction.
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Start this chapter free →States of Matter — FAQs
What are the key concepts in Class 11 Chemistry States of Matter?+
Whether a substance is a gas, a liquid or a solid is decided by a tug of war between the intermolecular forces pulling its particles together and the thermal energy driving them apart. This chapter first surveys those forces — London dispersion, dipole-dipole and hydrogen bonding — and then studies the gaseous state in detail: the laws of Boyle, Charles, Gay-Lussac and Avogadro, which combine into the ideal gas equation PV = nRT, together with Dalton's law of partial pressures and Graham's law of diffusion. The kinetic molecular theory explains why these laws work and introduces the Maxwell distribution of molecular speeds. Finally, real gases are shown to deviate from ideality at high pressure and low temperature, a deviation measured by the compressibility factor and described by the van der Waals equation, which leads on to critical constants, liquefaction and the properties of the liquid state. Key ideas include London dispersion forces, Dipole-dipole interaction, Hydrogen bonding, Boyle's law.
What does Class 11 Chemistry Chapter 305 (States of Matter) cover on XamBaaz?+
It has 40 NCERT-based MCQs on "States of Matter": 20 Easy and 20 Medium. Together they make 4 timed quizzes, and you never get the same set twice. Every question has an instant explanation. They help you prepare for CBSE & Maharashtra HSC Board exams, JEE Main, MHT-CET, JEE Advanced and NEET UG.
Are these "States of Matter" questions free to practise?+
Yes. Sign in with Google to practise "States of Matter" free. Full unlimited access is ₹999/year on a launch offer until 1 December 2026. No chapter is charged separately.
How should I revise "States of Matter" for the exam?+
Start with the Easy quiz to check your basics, then try Medium to practise applying them. There are 4 timed quizzes on this chapter, so you can come back for a fresh set instead of one you have seen. Read each explanation, retry the questions you miss, and track your accuracy until it stays high.
Are these "States of Matter" MCQs available with answers?+
Yes. 6 sample questions are shown here in full, each with the correct option and a step-by-step "Why" explanation. Sign in free with Google to start practising, with instant scoring.
Is there negative marking in the "States of Matter" quizzes?+
Yes. The timed quizzes use exam-style marking: +4 for a right answer, −1 for a wrong one and 0 for a skip, the same negative marking as JEE Main, JEE Advanced and NEET UG. MHT-CET and CBSE board papers have no negative marking. Our mocks for those are scored their way.
What are the important questions from States of Matter (Class 11 Chemistry)?+
The questions that matter most test London dispersion forces, Dipole-dipole interaction, Hydrogen bonding, Boyle's law. This page shows 6 solved important MCQs with answers and explanations; all 40 questions on the chapter are available as timed quizzes once you sign in.
Is there an online quiz for States of Matter?+
Yes — Class 11 Chemistry States of Matter has timed online quizzes at Easy and Medium levels, with instant scoring and a worked explanation on every question. The first quiz on the chapter is free.