chemistry MCQs - 11th class Chapter 06 Mcqs

1

The tendency of an atom to attract a shared electron pair towards itself is called its?

A

Ionization energy

B

Electron affinity

C

Electronegativity

D

Bond energy

2

According to the text, which element is assigned an arbitrary standard electronegativity value of 4.0?

A

Oxygen

B

Chlorine

C

Fluorine

D

Nitrogen

3

A chemical bond formed by the complete transfer of electrons is called a(n) ________ bond.

A

Covalent

B

Ionic

C

Coordinate covalent

D

Metallic

4

What is the bond distance of a H-H molecule as mentioned in the potential energy curve diagram?

A

75.4 pm

B

436.45 pm

C

109.5 pm

D

154 pm

5

The amount of energy evolved when two hydrogen atoms form a molecule is?

A

75.4 kJ/mol

B

109.5 kJ/mol

C

348 kJ/mol

D

436.45 kJ/mol

6

Which of the following is NOT a reason why the radius of an atom cannot be determined precisely?

A

There is no sharp boundary of an atom

B

The electronic probability distribution is affected by neighbouring atoms

C

The size of an atom is constant in all compounds

D

The probability of finding an electron never becomes exactly zero

7

In the periodic table, atomic radii generally ________ from left to right in a period.

A

Increase

B

Decrease

C

Remain the same

D

First increase, then decrease

8

The ionic radius of a cation is ________ than the atomic radius of the parent atom.

A

Larger

B

Smaller

C

Equal

D

Sometimes larger, sometimes smaller

9

The covalent radius of a carbon atom is calculated to be?

A

99.4 pm

B

176.7 pm

C

77.3 pm

D

37.7 pm

10

What is the first ionization energy of Magnesium (Mg) as per the text?

A

419 kJmol⁻¹

B

738 kJmol⁻¹

C

520 kJmol⁻¹

D

1450 kJmol⁻¹

11

Which factor does NOT influence ionization energy?

A

Atomic radius

B

Nuclear charge

C

Number of isotopes

D

Shielding effect

12

In a group, ionization energy generally decreases due to?

A

Increase in nuclear charge

B

Successive addition of electronic shells

C

Decrease in atomic size

D

Increase in electronegativity

13

The energy released when an electron adds to an isolated gaseous atom is called?

A

Ionization energy

B

Electron affinity

C

Lattice energy

D

Bond energy

14

A difference of how many units in electronegativity shows roughly equal contributions of ionic and covalent bonds?

A

1.0

B

1.5

C

1.7

D

2.0

15

Which type of bond is formed when the shared pair of electrons is donated by only one of the bonded atoms?

A

Ionic bond

B

Covalent bond

C

Coordinate covalent bond

D

Hydrogen bond

16

In the formation of the NH3-BF3 complex, which molecule acts as the electron pair donor (Lewis base)?

A

BF3

B

NH3

C

Both

D

Neither

17

According to VSEPR theory, the geometry of a BeCl2 molecule is?

A

Bent

B

Linear

C

Trigonal planar

D

Tetrahedral

18

The order of repulsion strength between electron pairs is?

A

lp-lp > lp-bp > bp-bp

B

bp-bp > lp-bp > lp-lp

C

lp-bp > lp-lp > bp-bp

D

lp-lp > bp-bp > lp-bp

19

What is the shape of an ammonia (NH3) molecule?

A

Tetrahedral

B

Trigonal planar

C

Trigonal pyramidal

D

Bent

20

The bond angle in a water (H2O) molecule is approximately?

A

109.5°

B

107.5°

C

120°

D

104.5°

21

In sp³ hybridization, how many hybrid orbitals are formed?

A

Two

B

Three

C

Four

D

Five

22

The geometry of a methane (CH4) molecule with sp³ hybridization is?

A

Square planar

B

Trigonal planar

C

Linear

D

Tetrahedral

23

Ethene (C2H4) molecule involves which type of hybridization for its carbon atoms?

A

sp

B

sp²

C

sp³

D

dsp²

24

A pi (π) bond is formed by the ________ overlap of p-orbitals.

A

End-to-end

B

Sideways

C

Head-on

D

s-p overlap

25

The bond order of a nitrogen molecule (N2) is?

A

1

B

2

C

3

D

0

26

The paramagnetism of an oxygen (O2) molecule is explained by?

A

VSEPR Theory

B

Valence Bond Theory

C

Molecular Orbital Theory

D

Lewis Theory

27

The bond energy of a C-C single bond is given as?

A

614 kJmol⁻¹

B

839 kJmol⁻¹

C

348 kJmol⁻¹

D

413 kJmol⁻¹

28

Which of the following bonds is the strongest?

A

C-C

B

C=C

C

C≡C

D

C-H

29

A dipole moment is the product of electric charge (q) and the ________.

A

distance between charges (r)

B

bond energy

C

electronegativity

D

atomic mass

30

The unit for measuring dipole moment mentioned in the text is?

A

Joule

B

Pascal

C

Debye

D

Kelvin

31

Which of the following molecules has a zero dipole moment?

A

H2O

B

NH3

C

HF

D

CO2

32

Ionic compounds are generally soluble in ________ solvents.

A

Polar

B

Non-polar

C

Organic

D

All types of

33

The phenomenon of isomerism is typically exhibited by ________ compounds.

A

Ionic

B

Covalent

C

Metallic

D

Noble gases

34

Reactions between ionic compounds in aqueous solution are generally ________.

A

Slow

B

Rapid

C

Moderate

D

Reversible

35

The shape of molecules with AB3 type and one lone pair (e.g., SnCl2) is?

A

Linear

B

Trigonal planar

C

Bent or angular

D

Tetrahedral

36

The hybridization of the central boron atom in BF3 is?

A

sp

B

sp²

C

sp³

D

sp³d

37

How many sigma (σ) and pi (π) bonds are present in an ethyne (C2H2) molecule?

A

One σ, two π

B

Two σ, one π

C

Three σ, two π

D

Two σ, three π

38

In the molecular orbital diagram of O2, the unpaired electrons are located in which orbitals?

A

σ(2p)

B

π(2p)

C

π*(2p)

D

σ*(2s)

39

The bond order for a Helium molecule (He2) is calculated to be?

A

1

B

2

C

0.5

D

0

40

The increase in the size of an anion is due to?

A

Increased nuclear charge

B

Loss of electrons

C

Increase in electron-electron repulsion

D

Decrease in shells

41

In the formation of KCl, the energy released during the formation of the crystal lattice is called?

A

Ionization energy

B

Electron affinity

C

Bond energy

D

Lattice energy

42

CsF has what percentage of ionic character according to the text?

A

72%

B

100%

C

92%

D

50%

43

A molecule like CCl4 is non-polar overall due to its ________.

A

Polar bonds

B

High electronegativity

C

Symmetry

D

Low boiling point

44

What is the bond angle in a molecule with trigonal planar geometry like BH3?

A

109.5°

B

180°

C

120°

D

90°

45

In NH3, the bond angle is compressed from the ideal 109.5° to 107.5° due to?

A

Repulsion from the lone pair

B

The small size of nitrogen

C

The high electronegativity of hydrogen

D

The presence of d-orbitals

46

A double bond consists of?

A

Two sigma bonds

B

Two pi bonds

C

One sigma and one pi bond

D

One sigma and two pi bonds

47

The formation of a H2 molecule from two H atoms is an ________ process.

A

Exothermic

B

Endothermic

C

Isothermal

D

Isobaric

48

The covalent radius of a hydrogen atom is?

A

75.4 pm

B

37.7 pm

C

154 pm

D

99.4 pm

49

The first ionization energy of Sodium (Na) is ________ than that of Magnesium (Mg).

A

Higher

B

Lower

C

Equal

D

Cannot be compared