Chemistry Gases MCQs Chapter 3 Class 11

Chemistry Gases MCQs – Chapter 3 Class 11

Chemistry Gases is an important chapter of Class 11 Chemistry and has high weightage in FSc Part-I exams and entry test preparation. MCQs from this chapter are frequently asked in MDCAT, NUMS, AKU, NUST, UET ECAT, and board examinations. This chapter covers key topics such as gas laws, Boyle’s law, Charles’ law, Avogadro’s law, ideal gas equation, kinetic molecular theory, diffusion, effusion, and real gases.

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Created on February 10, 2022 By Ali Durrani

Chemistry Ch 3 Class 11 States of Matter – Gases

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1 / 63

A child’s balloon has a volume 3.80 dm3, when the temperature is 35°C. If the balloon is put in a refrigerator and cooled to 5°c, the approximate volume of the balloon is (assume pressure inside the balloon is equal to atmospheric pressure):

NTS 2011
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 3.00 dm3

B) 3.43dm3

C) 3.08 dm3

D) 3.25 dm3

2 / 63

Which of the following gas is more ideal at STP?

NUMS 2015
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) SO2

B) NH3

C) H2

D) H2S

3 / 63

Statement of Charles Law:

V is directly proportional to P

V is directly proportional to T

) P is inversely proportional to V

d) All of these

4 / 63

The compression factor (compressibility factor) for one mole of a Van der Waals gas at 0 and 100 atmosphere pressure is found to be 0.5. Assuming that the volume of gas molecule is negligible, calculate the Van der Waals constant ‘a’.

NUMS 2015
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 1.254

B) 2.87

C) 3.76

D) 1.34

5 / 63

What is the volume in cm3 of 3.01 x 10^23 molecules of O2 gas at S.T.P.?

NTS 2017
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 1000 cm3

B) 11000 cm3

C) 1120 cm3

D) 11200 cm3

6 / 63

At the transition temperature of a crystalline solid, the substance exists:

NUMS 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) In most stable geometric form

B) Solid and liquid state

C) In dynamic equilibrium between two crystalline forms

D) In one solid geometrical form only

7 / 63

Glass is a/an:

NTS 2014
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Pure solid

B) Supercooled liquid

C) Mixture of sodium and calcium

D) Crystalline form of Na2CO3

8 / 63

A sample of gas weighs 1.25 g, at 28 C occupying a volume of 2.50 x 10-2 ml and its pressure is 715 torr. What is the molar mass in grams?

NTS 2016 DUHS & JSMU
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 131.1

B) 1.311

C) 1.212

D) 122.1

9 / 63

Solid CO2 dry ice has a structure just like:

NUMS 2014
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Diamond

B) Sulphur

C) Graphite

D) None of the above

10 / 63

What assumptions are made in the Kinetic Theory about an ideal gas?

There are no forces of attraction between molecules
the molecules are in a state of continuous random motion
the size of the molecule is negligible
NTS 2015 SMBBMC
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

B) II ONLY

C) I AND II ONLY

D) II AND III ONLY

E) I, II, III

11 / 63

When does a gas deviate the most from its ideal behavior ?

NTS 2010
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) At low pressure and high temperature

B) At high pressure and high temperature

C) At low pressure and low temperature

D) At high pressure and low temperature

12 / 63

Excluded volume is not equal to the actual volume of gas molecules and is represented by:

13 / 63

If we take some water at 0oC and start heating it,we find that in the temperature range 0oC to 4oC:

NUMS 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) It expands on heating

B) It contracts on heating

C) Both

D) None

14 / 63

How many balloons of capacity 0.25dm3 at 1atm pressure can be filled from a hydrogen gas cylinder of 5dm3 capacity at 10 atm?

NUMS 2015
Chemistry
States of Matter – Gases, Liquids and Solids
States of Matter
Elimination Tool:

A) 50

B) 90

C) 180

D) 200

15 / 63

When an element exists in more than one crystalline form, the phenomenon is termed as:

NTS 2010
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Isomorphism

B) Allotropy

C) Isomerism

D) Anisotropy

16 / 63

Matter changes from one state to another state on change in ___________.

NTS 2015 SMBBMC
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) density

B) pressure

C) viscosity

D) all

17 / 63

Solid NaCl is a bad conductor of electricity because:

NUMS 2016
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Solid NaCl is covalent

B) In the solid state, there are no ions

C) In solid NaCl. there is no migration of ions

D) In solid NaCl, there are not electron

18 / 63

When Gypsum is heated to about 100° C, it losses some water of crystallization and becomes:

NTS 2011
Chemistry
States of Matter – Gases, Liquids and Solids
s and p Block Elements
Elimination Tool:

A) Epsom salt

B) Kieserite

C) Plaster of Paris

D) Bleaching Powder

19 / 63

For a given mass of gas, if the pressure is reduced to half and its temperature is doubled, then volume V will become?

NTS 2015 SMBBMC
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 4V

B) 2V2

C) V/4

D) 8V

20 / 63

If the matter in a given system at a given condition is divided into two equal parts, then the value of the extensive properties will become:

NTS 2011
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Double of the original value

B) Half of the original value

C) Remain the same as the original value

D) One-fourth of the original value

21 / 63

Choose the correct statement:

NUMS 2014
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Diamond is the hardest and graphite is softest

B) Graphite is the hardest while lamp black is softest

C) Coal is the hardest and coke is softest

D) Diamond is the hardest and coke is softest

22 / 63

The internal energy of an ideal gas depends upon its:

NTS 2016 DUHS & JSMU
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Molecular size

B) Pressure only.

C) Volume only

D) Temperature only

23 / 63

Gases can be converted into liquid by:

Increasing temperature and decreasing pressure

Decreasing temperature and increasing pressure

Same temperature and pressure

Increasing pressure and temperature

24 / 63

A graph between volume and temperature gives a straight line which cuts the temperature axis at:

NUMS 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 0 C

B) 273 C

C) 546 C

D) -273 C

25 / 63

Statement of Graham’s Law is

The rate of diffusion is directly proportional to the square root of its density

The rate of diffusion is inversely proportional to the square of its density

The rate of diffusion is inversely proportional to its density.

The rate of diffusion is inversely proportional to the square root of its density

26 / 63

An example of a solution not in equilibrium is:

NTS 2016 DUHS & JSMU
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) chemical pH indicator

B) acid/base buffer

C) anhydrous solution

D) hypotonic solution

27 / 63

Acetone and Chloroform are soluble into each other due to:

NUMS 2015
Chemistry
Chemical Bonding
States of Matter
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Hydrogen bonding

B) Dipole – dipole interaction

C) London forces

D) Both (a) and (b)

28 / 63

The unit of viscosity is:

NTS 2012
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Joule

B) N/m2

C) Dynes/cm

D) Poise

29 / 63

The value of S.T.P for 1 mole of any ideal gas is:

NUMS 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 273.16 K and 1 atm

B) 0 C & 1 mm Hg

C) 273 16 C & 1 atm

D) 0 K & 1 atm

30 / 63

The Vander Waal’s constant ‘If of a gas Is four times the:

Actual volume

Volume of vessel

free volume

Volume

31 / 63

Which of the following is constant during an isothermal process?

Volume

Pressure

Temperature

Both b and c

32 / 63

Comparative rates of diffusion of He and SO2 will be _______.

NTS 2012
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 8

B) 2

C) 4

D) 16

33 / 63

Upon which factor is vapour pressure not dependent:

NUMS 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Temperature

B) Intermolecular forces

C) Density of liquid

D) Surface area of liquid

34 / 63

Real gases behave ideally at:

NTS 2018
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Low temperature and low pressure

B) Moderate temperature and low pressure

C) High temperature and low pressure

D) High temperature and high pressure

35 / 63

According to Charles Law, when temperature is reduced to half the volume will be

Doubled

Half

Quarter

Same as original

36 / 63

According to the general gas equation, density of an ideal gas depends upon:

PMC 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Pressure

B) Temperature

C) Molar Mass

D) All of these

37 / 63

Real gases deviate significantly from ideal gas behavior at

Low temperature and high pressure

High temperature and low pressure

None of these

Noth a and b

38 / 63

Which of the following statements is true of Amorphous solids?

NTS 2011
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) They possess symmetry

B) They are isotropic

C) They are anisotropic

D) They cleave along a particular direction

39 / 63

The stability of ionic crystal depends principally on:

NTS 2014
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) High electron affinity of anion forming species

B) Lattice energy of crystal

C) Low Ionization energy of cation forming species

D) Low heat of sublimation of cation forming solid

40 / 63

All the gasses at 212.44 cm3 have

Same mass

Different mass

Can't be predicted

None of these

41 / 63

Pressure remaining constant, at which temperature volume of gas will become twice to the volume at 0 C?

NUMS 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 546 C

B) 200 C

C) 546 K

D) 273 K

42 / 63

The crystals formed as a result of vander der Waals interactions are:

NTS 2010
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Molecular crystals

B) Covalent crystals

C) Metallic crystals

D) Ionic crystals

43 / 63

2 gasses at SIP, with equal volume and equal pressure will have same a

K.E

Mass

Number of molecule

Weight

44 / 63

Half atmospheric pressure is:

NUMS 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 400 torr

B) 50622 Pa

C) 101.3 Pa

D) 8.5 pounds

45 / 63

Diamond and Graphite:

NTS 2013
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) are isotopes

B) are isomers

C) are allotropes

D) have the same structure

46 / 63

1 atmospheric pressure is equal to

1kg/cm2

1.033 kg/cm2

1.1kg/cm2

1.133 kg/cm2

47 / 63

Which of the following pairs of gases have same rate of diffusion:

NTS 2017
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) CO2 and N2O

B) CO2 and CO

C) NO2 and CO2

D) CO2 and N2O4

48 / 63

Rate of effusion of a gas depends upon:

NUMS 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) size of pin hole

B) pressure

C) temperature

D) molecular mass

E) all of above

49 / 63

The actual volume of gas molecules is considered negligible at following pressures:

PMC 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 2 atm

B) 4 atm

C) 6 atm

D) 8 atm

50 / 63

Which of the following solids is an example of a substance with a macromolecular structure?

NUMS 2016
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Aluminium chloride

B) Ice

C) Magnesium oxide

D) Silicon (IV) oxide

51 / 63

Which of the following substances has giant covalent structure?

PMC 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Iodine crystal

B) Solid CO2

C) Silica

D) White phosphorus

52 / 63

When gases expand, this causes:

Cooling

Heating

Remain constant

None

53 / 63

A solid melts sharply just above 100 degree centigrade. it does not conduct electricity even when molten. It has weak Vander waal’s forces. What is the structure of the solid most likely to be?

NTS 2015 SMBBMC
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) An atomic crystal

B) ionic crystal

C) a molecular crystal

D) metallic

54 / 63

CO2 and SO2 both are tri-atomic molecules but heat of vaporization of SO2 is greater than that of CO2 due to:

PMC 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) High electronegativity of S

B) Greater size of SO2

C) SO2 is polar and CO2 is non-polar

D) SO2 is more acidic than CO2

55 / 63

950 torr corresponds to:

NTS 2010
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 3.5 atm

B) 1 atm

C) 3 atm

D) 1.25 atm

56 / 63

Gases behave ideal at

Low pressure and High temperature

low pressure and Low temperature

High temperature and Low pressure

High temperature and High pressure

57 / 63

The Unit cell with crystallographic dimensions a = b ≠c ,α = β = γ = 90 degrees is:

NTS 2015 DUHS and JSMU
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Cubic

B) Tetragonal

C) Monoclinic

D) Hexagonal

58 / 63

The expression PV = nRT represents the:

NUMS 2020
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Dalton’s Law

B) Avogadro’s Law

C) General gas equation

D) Van der Waals equation

59 / 63

1 liter of a gas weighs 2 g at 300 K and 1 atm pressure. If the pressure is made 0.75 atm, at which of the following temperatures will 1 L of the same gas weigh 1 g?

NTS 2017
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 450 K

B) 800 K

C) 600 K

D) 900 K

60 / 63

Which one is not related to evaporation?

NUMS 2015
Chemistry
Thermochemistry
States of Matter
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Continuous

B) Endothermic

C) Exothermic

D) Spontaneous

61 / 63

Liquid crystals are used for:

Making LCD

Making thermometers

Optical Imaging

All of these

62 / 63

What is the temperature at which the volume of gas is said to be zero?

NTS 2015 SMBBMC
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) 0 C

B) 4 C

C) -273.16 C

D) -173.16 C

63 / 63

A crystal system having all sides (a, b and c) unequal and anglesα = β = γ= 90 is:

NUMS 2015
Chemistry
States of Matter – Gases, Liquids and Solids
Elimination Tool:

A) Cubic

B) Rhombohedral

C) Orthorhombic

D) Hexagonal

Your score is

The average score is 60%

Importance of Gases MCQs

A strong understanding of gases helps students solve numerical problems related to pressure, volume, temperature, and moles. Most exams include calculation-based MCQs from gas laws and the ideal gas equation. Practicing chapter-wise MCQs improves numerical solving skills, accuracy, and confidence for competitive exams.

Effective Strategy for Free Preparation

For effective preparation, students should revise gas laws and formulas regularly, practice numericals step by step, and solve topic-wise MCQs consistently. Attempting free tests and past paper questions helps identify important concepts and repeated exam patterns. PLS Academy provides structured MCQs and free resources to support Chemistry Gases preparation and other Class 11 Chemistry chapters.

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