Category: Class 11 Chemistry Objective Questions

Chemistry Multiple Choice Questions on “States of Matter – Intermolecular Forces”.

1. What are the forces of attraction and repulsion between interacting molecules known as _________
a) attractive forces
b) repulsive forces
c) intermolecular forces
d) intramolecular forces
Answer: c
Clarification: Intermolecular means between molecules and intramolecular means within in molecule. Both attractive and repulsive forces include intermolecular forces. Therefore, the forces of attraction and repulsion between interacting molecules are known as Intermolecular forces.

2. Deviation of real gas behavior from ideal gas is discovered by _____________
a) Jonathan
b) Van der Waals
c) Boyle
d) Newland
Answer: b
Clarification: A Dutch scientist named Johannes van der Waals found out the reason for real gas behavior’s deviation from ideal gas behavior. And he said that those forces which were named van der Waals were responsible.

3. London force is also known as _____________
a) dispersion force
b) van der Waals forces
c) hydrogen bonding
d) covalent bonds
Answer: a
Clarification: Electrically symmetrical atoms and non-polar molecules having zero dipole movement due to their electron distribution may sometimes develop a momentary dipole also known as London force or the Dispersion forces.

4. Dispersion force’s interaction energy is proportional to (take “r” as the distance between the two particles) ___________
a) r⁶
b) 1/r^-6
c) r²
d) 1/r⁶
Answer: d
Clarification: The interaction energy between two atoms or molecules experiencing dispersion or London forces is inversely proportional to the sixth power of the distance between those molecules when found, experimentally.

5. Dipole-Dipole forces are stronger than _______ and weaker than _________ interactions.
a) dipole-induced dipole, london
b) ion-ion, dispersion
c) ion-ion, london
d) london, ion-ion
Answer: d
Clarification: Dipole-Dipole forces are stronger than London forces and weaker than ion-interactions. As only the partial charges are involved. London forces have no charges, and ion-ion forces have full charges.

6. HCl is an example of __________
a) dipole-dipole intercations
b) dipole-induced dipole interactions
c) london intercation
d) van der waals interaction
Answer: a
Clarification: Dipole-Dipole interactions occur between molecules having permanent dipoles. And also the ends of dipoles posses partial charge which represented by a Greek letter δ. In an HCl molecule, the same type of interactions occur.

7. Take “r” as the distance between two molecules. The energy between stationary polar molecules is proportional to ____________ in the case of dipole-dipole intercations.
a) 1/r³
b) r³
c) r²
d) 1/r²
Answer: a
Clarification: The energy between two polar molecules which are stationary, is inversely proportional to the cube of the distance between the molecules, in the case of dipole-dipole intercations. This interaction is stronger than the London forces.

8. Which of the following interaction occurs between a permanent dipole and a neutral molecule?
a) Dipole-Dipole interactions
b) Dipole-induced dipole interactions
c) London interaction
d) Van der Waals interaction
Answer: b
Clarification: Dipole-induced dipole interactions occur between a molecule of permanent dipole and molecule lacking permanent dipole. The dipole gets induced to the other molecule in this particular interaction.

9. Hydrogen bond plays a vital role in determining substance properties and structure. Which of the following may not an example?
a) Proteins
b) Nucleic acids
c) Methane molecule
d) Water
Answer: c
Clarification: As per the above statement, substance properties and structure is determined as per the hydrogen bond present in them, but in a methane molecule, there is no hydrogen bond. So it may not be an example.

10. Molecules do exert repulsive forces on one other.
a) True
b) False
Answer: a
Clarification: When two molecules come closer, the electron clouds between them they repel. This is the reason why solids and liquids cannot be easily compressed. As the distance between molecules decreases, the repulsive forces become much stronger.

Chemistry Multiple Choice Questions & Answers (MCQs) on “States of Matter – Liquefaction of Gases”.

1. Which of The following is a critical temperature for Carbon dioxide?
a) 32-degree centigrade
b) 30.98-degree centigrade
c) 40-degree centigrade
d) 30.91 degree Kelvin
Answer: b
Clarification: The critical temperature of carbon dioxide is a maximum temperature where the carbon dioxide can remain as a liquid below this temperature. The carbon dioxide is gas so the critical temperature for Carbon dioxide is 30.98 degrees centigrade.

2. Which of the following is Greater?
a) Boyle’s temperature
b) Boyle’s temperature = critical temperature
c) Critical temperature
d) Boyle’s temperature = 1/critical temperature
Answer: a
Clarification: Boyle’s temperature T_B is given by a/Rb critical temperature T_C is given by 8a/27Rb, where a is the pressure correction term and b is a volume correction term as per van der Waal’s equation. So Boyle’s temperature is greater than the critical temperature.

3. What is the ratio of critical temperature to Boyle’s temperature of the same gas?
a) 8/27
b) 27/8
c) 8
d) 27
Answer: a
Clarification: The maximum temperature gas can remain liquid is known as critical temperature. The temperature till which a gas behaves like an ideal gas is Boyle’s temperature. Boyle’s temperature T_B is given by a/Rb critical temperature T_c is given by 8a/27Rb. So the ratio is 8/27.

4. A fluid is a _______________
a) gas
b) liquid
c) solid
d) both gas and liquid
Answer: d
Clarification: A fluid is a gas or liquid that can be used to recognize the continuity. The fluid is something deforms under shear stress application and flows from one place to another, it is also a subset of States of matter.

5. A gas that is liquefied by applying pressure below critical temperature is called ____________ of the substance.
a) vapor
b) liquid
c) solid
d) plasma
Answer: a
Clarification: At critical temperature liquid state changes into gaseous state continuously the surface that separates both this state disappears and gas below critical temperature can be liquefied by applying pressure and this is called vapor of the substance.

6. If the value of a is greater, what does it mean?
a) the gas liquefies easily
b) the gas cannot liquify easily
c) gas obeys ideal gas law
d) gas particles have random motion
Answer: a
Clarification: The value of an in van der Waals equation is a measure of the magnitude of intermolecular attractive forces within a gas. It is independent of temperature and pressure. As attractive forces are more, the gas can be liquefied easily.

7. Which of the following can be the value of “b” for Helium?
a) 23.71 x 10^-6 m²/mol
b) 23.71 x 10^-6 m³/mol
c) 23.71 x 10^-6 m³ mol
d) 23.71 x 10^-6 m/mol
Answer: b
Clarification: From van der Waal’s equation (P – an²/V²)(V – nb) = nRT, we have that units of volume and number of moles x b are same. So L = mol x b; units of b is L/mol otherwise can be written as m³/mol.

8. The value of b for carbon dioxide is given as 42.69 x 10^-6m³/mol. What do you think is the volume of a molecule?
a) 7.59 m³
b) 7.03 m³
c) 76.09 m³
d) 7.09 m³
Answer:d
Clarification: From van der Waal’s equation (P – an²/V²)(V – nb) = nRT, we know that V = b/NA = 42.69 x 10^-6m³/mol/6.023 x 1023 molecules/mol. That equals 7.09 m³/molecule. So the volume of a molecule is 7.09m³.

9. In van der Waal’s equation, b is known as ______________
a) volume constant
b) pressure constant
c) volume correction
d) pressure correction
Answer: c
Clarification: In the van der Waal’s equation (P – an²/V²)(V – nb) = nRT, b is the volume correction term and is 4 times as the volume of a molecule. The letter a is the pressure correction term in the van der Waal’s equation.

10. Which of the following is an expression for Boyle’s temperature?
a) a/Rb
b) 27a/R
c) a/b
d) Ra/8b
Answer: a
Clarification: Boyle’s temperature T_b is given a/Rb, where a and b are the van der Waal’s constants for pressure and volume correction. The temperature till which a gas behaves like an ideal gas is Boyle’s temperature.

Chemistry Question Bank for Class 11 on “Ionic Equilibrium in Solution”.

1. CH₃COOH (rightleftharpoons) CH₃COO^– + H⁺ is in __________________
a) ionic equilibrium
b) chemical equilibrium
c) dynamic equilibrium
d) physical equilibrium
Answer: a
Clarification: The equilibrium that is attained between the ionized molecules and the ions in the solution of weak electrolyte is called Ionic Equilibrium. CH₃COOH (rightleftharpoons) CH₃COO^– + H⁺ is an example; CH₃COO^– and H⁺ are ions.

2. Electrolytes conduct electricity.
a) True
b) False
Answer: a
Clarification: Chemical substances which can conduct electricity in their Aqua state or in the molten state are called electrolytes. The conduction of current through the electrolyte is due to the movement of Ions, hence the above statement is true.

3. Which of the following may not be a strong electrolyte?
a) hydrochloric acid
b) sulfuric acid
c) nitric acid
d) ammonia
Answer: d
Clarification: Electrolytes which dissociate almost completely into constituent ions in aqueous solutions are known as strong electrolytes. Therefore ammonia is not a strong electrolyte because it can’t dissociate completely.

4. All organic acids except sulfonic acid are _____________ electrolytes.
a) weak
b) strong
c) not
d) neither strong nor weak
Answer: a
Clarification: Electrolytes which dissociate into a lesser extent in aqua solution are called weak electrolytes. All organic acids except sulfonic acids and bases like Ammonia, Ammonium hydroxide, amines, etc are weak electrolytes.

5. Can nonelectrolytes conduct electricity?
a) yes
b) no
c) sometimes
d) cannot say
Answer: b
Clarification: Michael Faraday classified substances into two categories; one is electrolytes and nonelectrolytes, nonelectrolytes do not dissociate into ions in a solution. So they do not conduct electricity.

6. Sugar solution __________ electricity.
a) do not conduct
b) conducts
c) depends on the type of sugar
d) cannot say
Answer: a
Clarification: Aqueous solution of sugar does not conduct electricity, but Aqueous solution of sugar conducts electricity. This is because the aqueous solution of sugar is a nonelectrolyte, whereas the salt solution is an electrolyte.

7. Which of the following is in Ionic Equilibrium?
a) 2AgI + Na₂S (rightleftharpoons)Ag₂S + 2NaI
b) 4 NH₃ + 5 O₂ (rightleftharpoons)4 NO + 6 H₂O
c) TiCl₄ + 2 H₂O (rightleftharpoons)TiO₂ + 4 HCl
d) H₂O + H₂O (rightleftharpoons)H₃O⁺ + OH^–
Answer: d
Clarification: Only H₂O + H₂O (rightleftharpoons)H₃O⁺ + OH^– is in ionic equilibrium. As the equilibrium established between the unionized molecules and the ions in the solution of weak electrolytes is known as Ionic Equilibrium.

8. What is the degree of dissociation for strong electrolytes?
a) 1
b) 0
c) less than 1
d) greater than 1
Answer: a
Clarification: Degree of dissociation is the fraction of the total number of molecules which dissociate into constituent ions, it is represented by the symbol ɑ. As a strong electrolyte dissociate completely, it values is 1.

9. Degree of dissociation does not depend on which of the following factors?
a) nature of the solute
b) nature of the solvent
c) sound
d) concentration
Answer: c
Clarification: Values of the degree of dissociation or degree of ionization depends upon the following factors: 1) the nature of the solute, 2) the nature of the solvent 3) concentration and 4) temperature of the solution.

10. K in K = Cα²/1 – ɑ represents ___________
a) dissociation constant
b) molar concentration
c) degree of dissociation degree of ionization
d) degree of ionization
Answer: a
Clarification: The above equation represents Ostwald’s dilution law, where K is the dissociation constant, C is the molar concentration of the solution and ɑ is a degree of dissociation or degree of ionization of the solution.

To practice Chemistry Question Bank for Class 11,

Chemistry Multiple Choice Questions on “s-Block Elements – Anomalous Properties of Lithium”.

1. Lithium and magnesium are ____________ metals.
a) sponge
b) hard
c) soft
d) smooth
Answer: b
Clarification: Lithium and magnesium are harder than other metals in the group because they have a strong metallic bond among themselves. This is one of the similarities between Lithium and magnesium having a diagonal relation.

2. Lithium chloride is ____________ in nature.
a) soft
b) covalent
c) ionic
d) complex
Answer: b
Clarification: Both lithium chloride (LiCl) and magnesium chloride (MgCl) are predominantly covalent when compared to other elements in their respective groups, that is alkali metals and alkaline earth metals.

3. What is the difference between the Ionic radius of cations of Lithium and magnesium?
a) 2 A°
b) 0.05 A°
c) 1 A°
d) 5 A°
Answer: b
Clarification: The Ionic radius of Lithium cation is 0.60A°, which is very close to that of magnesium cation that is 0.65A°, therefore the difference between the Ionic radius of cations of Lithium and magnesium is 0.05A°.

4. What is the electronegativity of lithium?
a) 2
b) 1
c) 5
d) 4
Answer: b
Clarification: Electronegativity of Lithium is 1.0 and the electronegativity of magnesium as 1.2, they have almost similar electronegativities which is one of the reasons for Lithium and Magnesium’s diagonal relationship.

5. Which of the following statements is true regarding the diagonal relationship between Lithium and magnesium?
a) Lithium and magnesium combined with oxygen to form superoxides
b) Lithium and magnesium are soft metals
c) Lithium hydroxide and magnesium Hydroxide are weak bases
d) Magnesium chloride is completely soluble in water
Answer: c
Clarification: The correct statements of the incorrect ones are that; Lithium and magnesium combine with oxygen in order to form monoxides, they are hard metals and magnesium chloride is partially soluble in water as lithium chloride.

6. Which of the following element has the smallest size in its group?
a) sodium
b) rubidium
c) potassium
d) lithium
Answer: d
Clarification: The element Lithium whose atomic number is given by 3 is the smallest element in its group that is alkali metals by size. This is one of the reasons why it has anomalous behavior in the periodic table comparatively.

7. Does Lithium react with nitrites?
a) yes
b) no
c) may be
d) may not be
Answer: a
Clarification: Yes, Lithium which is unlike the other alkali metals, reacts with nitrogen to form the nitride six moles of lithium combine with one mole of a nitrogen atom, in order to form two moles of lithium nitride.

8. On heating lithium carbonate decomposes in order to evolve the ____________
a) nitrogen
b) oxygen
c) carbon dioxide
d) lithium
Answer: c
Clarification: Lithium carbonate decomposes on heating in order to avoid carbon dioxide whereas other alkali metal carbonates do not evolve carbon dioxide, this occurs because lithium carbonate is unstable in the presence of heat and is the least stable among the carbonates of alkali metals.

9. Lithium has a diagonal relationship with ____________
a) magnesium
b) sodium
c) aluminum
d) neon
Answer: a
Clarification: Lithium shows diagonal resemblance with magnesium which is an element of group 2 and this resemblance is due to the similar polarising power of both these elements. polarizability is proportional to the ionic charge / the square of the Ionic radius.

10. Lithium has the same radius that of magnesium.
a) true
b) false
Answer: b
Clarification: The atomic radius of Lithium is 1.31Ao while that of magnesium is 1.34Ao, though Lithium and magnesium do not have the same radius, they have a similar radius which is a reason for their diagonal relationship.

Chemistry Multiple Choice Questions on “Organic Chemistry – Isomerism”.

1. 2-chloropropane and 1-chloropropane exhibit ____________ isomerism.
a) chain
b) position
c) functional
d) metamerism
Answer: b
Clarification: When two or more compounds have the same molecular formula but the different position of functional groups are substituents, they are called positional isomers and the phenomenon is called position isomerism. Here 2-chloropropane and 1-chloropropane differ in position so they exhibit position isomerism.

2. Which of the following is not a type of structural isomerism?
a) geometric isomerism
b) chain isomerism
c) metamerism
d) tautomerism
Answer: a
Clarification: Structural isomerism is a type of isomerism, compounds have the same molecular formula but different structures there can be further divided into types: chain isomerism, position isomerism, functional isomerism, metamerism, and tautomerism. Therefore geometric isomerism is not a type of structural isomerism.

3. Optical isomerism is a type of ____________
a) metamerism
b) stereoisomerism
c) geometrical isomerism
d) tautomerism
Answer: b
Clarification: The compounds having the same molecular formula but the different spatial arrangement of atoms or groups are stereoisomers and the phenomenon is called stereoisomerism. it is of three types namely optical isomerism, geometrical isomerism, and conformations.

4. The d-form is also known as ____________
a) rotatory
b) laevorotatory
c) dextrorotatory
d) l-form
Answer: c
Clarification: The isomer which rotates the plane of polarized light towards the right that is clockwise, is known as a dextrorotatory or d form while that which rotates towards the left that is anti-clockwise, is known as laevorotatory or l-form.

5. Enantiomers are same as diastereomers.
a) true
b) false
Answer: b
Clarification: In optical isomerism, enantiomers are nonsuperimposable mirror images while diastereomers are the isomers which are nonsuperimposable and not related to each other as mirror images, they also have different physical and chemical properties.

6. How many planes of symmetry does a meso compound have?
a) 2
b) 1
c) 3
d) 4
Answer: b
Clarification: The compound whose half part of a molecule is a mirror image of the other half, is called meso form. Generally, a meso compound has two or more chiral centers and one plane of symmetry. the compound in meso form is optically inactive due to internal compensation.

7. If a compound has 3 chiral carbons What is the number of optically active isomers?
a) 9
b) 3
c) 4
d) 8
Answer: d
Clarification: The number of optically active isomers for a compound is given as 2ⁿ where, n represents the number of chiral carbons in that particular carbon, here as the compound has 3 chiral carbons n = 3, so the number of optically active isomers equals 2³ = 8.

8. Acetaldehyde and ethenol show ____________
a) stereoisomerism
b) metamerism
c) positional isomerism
d) tautomerism
Answer: d
Clarification: The compounds acetaldehyde and ethenol exhibit tautomerism. Tautomerism is a special type of functional isomerism which arises in carbonyl compounds containing α-hydrogen atom, it is a change of keto form to enol form.

9. A compound with the same molecular formula exists in two forms one is alcohol and the other is Ether, what type of isomerism does it show?
a) metamerism
b) positional isomerism
c) functional isomerism
d) chain isomerism
Answer: c
Clarification: Functional isomerism arises when two or more compounds having the same molecular formula but the different functional group. An example is that C₃H₆O represents an aldehyde as well as a Ketone, therefore we can say that the above compound which is alcohol, as well as Ether, shows functional isomerism.

10. What is the specific rotation if its observed rotation is given as 3x, its length is given as x and density is given as 3/y?
a) 2y
b) 3y
c) y
d) 4y
Answer: c
Clarification: The specific rotation is given by the expression observed rotation/length X density, here as observed rotation is given as 3x and its length is given as x, while the density is 3/y, the specific rotation equals 3x/x(y/3) = y.

Chemistry Multiple Choice Questions on “Importance of Chemistry”.

1. Patients suffering from AIDS can be helped using which of the following drugs?
a) Cisplatin
b) AZT (Azidothymidine)
c) Taxol
d) Codeine
Answer: b
Clarification: The drug AZT is used for preventing or treating AIDS, while cisplatin & taxol are for cancer and codeine is a sort of painkiller. The drug AZT is also known as Zidovudine. This drug AZT is an antiretroviral drug. It’s used along with other drugs as a combination.

2. What are the basic constituents of matter?
a) Atoms & Molecules
b) Atoms & Moles
c) Molecules & Ions
d) Nuclei & Ions
Answer: a
Clarification: Atoms & Molecules are the basic constituents because the matter is made up of molecules and a molecule is made of atoms. Ions are either positively or negatively charged particles. Nuclei are the central part of atoms. When seen in the microscopic level, atoms are the basic unit of matter.

3. Which of the following is a chemical change?
a) Conversion of water to ice
b) Rusting of iron
c) Crumpling a sheet of aluminum foil
d) Casting silver
Answer: b
Clarification: In rusting of iron, the oxidation state of iron changes, but in the conversion of water to ice, crumpling a sheet of aluminum foil and casting silver the chemical state remains same whereas the physical state changes. When iron is exposed to oxygen, iron oxide formation takes place.

4. What does Sushruta Samhita explain?
a) Alkanes
b) Alkynes
c) Noble gases
d) Alkalies importance
Answer: d
Clarification: Sushruta Samhita is written by Sushruta, It’s in Sanskrit and contains text about various medicinal sciences and surgical procedures. It’s an old ancient book of India. It has great historical importance as it contains the detailed procedures and the proper instruments needed.

5. Philosophy of changing substances into another form is called as _______
a) Physiology
b) Anatomy
c) Alchemy
d) Transformation
Answer: c
Clarification: Alchemy is the study of how a substance changes to other substances. It’s a very old study. In olden days, it used to be done in secrecy and was a mystery. It’s related to magic and astrology. The main thing practitioners concentrated in alchemy was turning lead into gold.

6. Rasopanishada says how the gunpowder mixture is used in war.
a) True
b) False
Answer: b
Clarification: The preparation of gun powder is explained in Rasopanishada. It’s an ancient alchemy book that describes gun powder. It also describes the making of fireworks with sulfur, saltpeter, charcoal, arsenic, camphor, mercury, etc.

7. What does the Elixir of life of do?
a) grants immortality
b) cures diseases
c) kills a person
d) cause an incurable disease
Answer: a
Clarification: “Elixir” is a magical or medical potion, that is used to prolong life to an infinite extent. This is one of the main purposes of the study of chemistry in olden days. It grants the person who drinks it with eternal life or youth. It’s sometimes equated with the philosopher’s stone.

8. The paintings on the walls of Ajanta and Ellora cave were based on ________
a) Varahmihir’s Brihat Samhitha
b) Sushruta Samhita
c) Rasopanishada
d) Charaka Samhita
Answer: a
Clarification: Varahmihir’s Brihat Samhitha is about how glutinous material is prepared and applications of it on roofs and walls of houses and temples. Ajanta and Ellora’s walls look bright for ages only because the science mentioned in this book. It contains the science of using fruits, plants, etc to paint.

9. Seeds of Manhua plant and oil of Eranda were used in making ________
a) cosmetic powder
b) color dye
c) perfume
d) soap
Answer: d
Clarification: Seeds of Manhua plant and oil of Eranda along with calcium carbonate were used in making soaps around the 18^th century in India as per history records.

10. Charaka Samhita is the oldest known book of Ayurvedic in India.
a) True
b) False
Answer: a
Clarification: Ayurveda is about the treatment of diseases. It also consists of nanotechnology. It also uses bhasma of metals for treatment. It’s proven that metal’s nanoparticles are present in bhasmas. it belongs to the 2^nd-century text and it has 8 books with 120 chapters.