chemistry MCQs - 11th class Chapter 04 Mcqs

1

Which of the following forces are called Debye forces?

A

Dipole-dipole forces

B

London dispersion forces

C

Ion-dipole forces

D

Dipole-induced dipole forces

2

The strength of dipole-dipole forces is approximately what percentage of a covalent bond's strength?

A

10%

B

1%

C

50%

D

25%

3

Who provided an explanation for the weak attractive forces between non-polar molecules in 1930?

A

Frederick Reinitzer

B

Fritz London

C

Drude

D

Loren

4

Which of the following is NOT a factor affecting the strength of London forces?

A

Size of electronic cloud

B

Number of atoms in the molecule

C

Shape of the molecule

D

Presence of lone pairs

5

The boiling point of which halogen is the highest?

A

Fluorine

B

Chlorine

C

Bromine

D

Iodine

6

Which hydrocarbon has the highest boiling point according to Table 4.2?

A

Methane

B

Hexane

C

Decane

D

Isodecane

7

Hydrogen bonding is an electrostatic force of attraction between a highly electronegative atom and a...?

A

Partially negatively charged hydrogen atom

B

Another electronegative atom

C

Partially positively charged hydrogen atom

D

A metal ion

8

The strength of a hydrogen bond is generally how many times less than a covalent bond?

A

5 times

B

10 times

C

20 times

D

50 times

9

In the hydrides of Group VI-A, which compound shows an exceptionally high boiling point due to hydrogen bonding?

A

H₂S

B

H₂Se

C

H₂Te

D

H₂O

10

How many hydrogen bonds can one water molecule form on average?

A

One

B

Two

C

Three

D

Four

11

Why does ice float on liquid water?

A

Ice is denser than water

B

Ice has empty spaces in its structure, making it less dense

C

Ice molecules have higher kinetic energy

D

Hydrogen bonds are weaker in ice

12

When water freezes, it occupies how much more space?

A

5%

B

7%

C

9%

D

12%

13

The adhesive property of paints and dyes is developed due to what?

A

London dispersion forces

B

Covalent bonding

C

Ionic bonding

D

Hydrogen bonding

14

The spontaneous change of a liquid into its vapours at all temperatures is called?

A

Boiling

B

Condensation

C

Evaporation

D

Sublimation

15

Vapour pressure of a liquid is the pressure exerted by the vapours in equilibrium with the liquid at a given...?

A

Pressure

B

Volume

C

Temperature

D

Surface area

16

According to Table 4.3, what is the vapour pressure of water at 100°C?

A

760 torr

B

527.8 torr

C

355.1 torr

D

149.4 torr

17

Which liquid has the highest vapour pressure at 20°C according to Table 4.4?

A

Glycerol

B

Mercury

C

Ethanol

D

Isopentane

18

The amount of heat required to vaporize one mole of a liquid at its boiling point is called?

A

Molar heat of fusion

B

Molar heat of sublimation

C

Molar heat of vaporization

D

Enthalpy change

19

At what pressure does water boil at 98°C at Murree hills?

A

760 torr

B

1489 torr

C

700 torr

D

323 torr

20

The process of distilling a liquid at a lower temperature under reduced pressure is called?

A

Fractional distillation

B

Steam distillation

C

Simple distillation

D

Vacuum distillation

21

Which term is defined as the amount of heat absorbed by one mole of a solid when it melts?

A

Molar Heat of Vaporization (ΔHv)

B

Molar Heat of Fusion (ΔHf)

C

Molar Heat of Sublimation (ΔHs)

D

Lattice Energy

22

Who discovered the property of liquid crystals in 1888 by studying cholesteryl benzoate?

A

Fritz London

B

Frederick Reinitzer

C

L. Pauling

D

Drude

23

A liquid crystalline state exists between which two temperatures?

A

Melting and boiling points

B

Freezing and melting points

C

Melting temperature and clearing temperature

D

Clearing and boiling temperatures

24

Liquid crystals used in the display of digital watches operate based on the effect of what on their weak bonds?

A

Temperature, pressure, and electro-magnetic fields

B

Only temperature

C

Only pressure

D

Only light

25

Substances whose constituent particles do not possess a regular orderly arrangement are called?

A

Crystalline solids

B

Ionic solids

C

Molecular solids

D

Amorphous solids

26

Which of the following is an example of an amorphous solid?

A

NaCl

B

Diamond

C

Glass

D

Ice

27

The property of crystalline solids to show variation in physical properties depending on the direction is called?

A

Isomorphism

B

Polymorphism

C

Anisotropy

D

Symmetry

28

The phenomenon in which two different substances exist in the same crystalline form is known as?

A

Allotropy

B

Isomorphism

C

Polymorphism

D

Anisotropy

29

A compound that exists in more than one crystalline form, such as CaCO₃, is called a?

A

Isomorph

B

Allotrope

C

Polymorph

D

Amorphous

30

The temperature at which two crystalline forms of the same substance can co-exist in equilibrium is called?

A

Melting point

B

Boiling point

C

Transition temperature

D

Clearing temperature

31

What is the smallest part of the crystal lattice that has all the characteristic features of the entire crystal?

A

Lattice site

B

Unit cell

C

Crystal system

D

Isomorph

32

How many crystal systems are there in total?

A

3

B

5

C

7

D

9

33

In which crystal system are all three axes of unequal length and all are at right angles to each other?

A

Cubic

B

Tetragonal

C

Orthorhombic

D

Monoclinic

34

Graphite and Ice belong to which crystal system?

A

Cubic

B

Hexagonal

C

Tetragonal

D

Triclinic

35

In which type of solids are particles held together by strong electrostatic forces between oppositely charged ions?

A

Ionic solids

B

Covalent solids

C

Metallic solids

D

Molecular solids

36

Why are ionic crystals brittle?

A

Due to non-directional forces

B

Due to repulsion between like ions when layers slide

C

Due to their high density

D

Due to the absence of free electrons

37

In the NaCl crystal structure, what is the coordination number of each Na⁺ ion?

A

4

B

6

C

8

D

12

38

How many NaCl formula units are present in one unit cell of sodium chloride?

A

1

B

2

C

4

D

8

39

What is lattice energy?

A

Energy absorbed to melt a solid

B

Energy released when one mole of ionic crystal is formed from gaseous ions

C

Energy required to vaporize a liquid

D

Energy to break covalent bonds

40

Which of the following is a covalent solid with a giant molecular structure?

A

Iodine

B

Diamond

C

Ice

D

Dry Ice (CO₂)

41

What is the bond angle in a diamond crystal?

A

120°

B

90°

C

180°

D

109.5°

42

In solid iodine, what type of forces hold the molecules together?

A

Ionic bonds

B

Covalent bonds

C

Metallic bonds

D

van der Waals forces

43

The 'electron pool' or 'electron gas theory' is used to explain bonding in which type of solids?

A

Ionic

B

Covalent

C

Molecular

D

Metallic

44

The ability of metals to be drawn into wires is called?

A

Malleability

B

Luster

C

Ductility

D

Conductivity

45

What is the name for the packing arrangement in metals described as ABAB... pattern?

A

Cubic close packing

B

Face-centered cubic

C

Body-centered cubic

D

Hexagonal close packing

46

Which type of crystalline solid is typically soft, easily sublime, and has a low melting point?

A

Ionic

B

Covalent

C

Metallic

D

Molecular

47

In the structure of diamond, what type of hybridization do the carbon atoms undergo?

A

sp

B

sp²

C

sp³

D

dsp²

48

Which of the following is an example of a molecular solid with polar molecules?

A

Iodine

B

Sulphur

C

Ice (H₂O)

D

Carbon dioxide

49

The electrical conductivity of metals generally ______ with an increase in temperature.

A

increases

B

decreases

C

remains constant

D

becomes zero

50

The phenomenon shown by an element existing in more than one crystalline form, such as carbon as diamond and graphite, is called?

A

Isomorphism

B

Polymorphism

C

Allotropy

D

Anisotropy